Challenges and Trends in Environmental Analytical Chemistry January – March 2018 Volume 5 Number 18
BrMASS - 8 to 12 December Windsor Hotel Barra da Tijuca 7th IBERO-AMERICAN CONFERENCE ON MASS SPECTROMETRY Five days of Conferences. More than 20 Plenary Talks. 50 Invited Guests. Your chance to strengthen your networks and deepen your understanding of Mass Spectrometry - all of this in one of Brazil´s most beautiful landscapes.
SPEAKERS MASS 2018 will feature over 48 speakers from all over the world, exposing their newest and brightest ideas on Mass Spectometry.
PROGRAM A CONFERENCE YOU WON´T SOON FORGET Five days of events, full with meetings & greetings, poster presentations, oral presentations, public performances and much more.
LATEST NEWS KEEP UP TO DATE WITH MASS SPECTROMETRY Get ready for BrMASS 2018! Here you will find the latest news about the topics and researches featured in our Congress
SPONSORS
WEBSITE
VisĂŁo Fokka - Comunication Agency
About Br. J. Anal. Chem. The Brazilian Journal of Analytical Chemistry (BrJAC) is a peer-reviewed scientific journal intended for professionals and institutions acting mainly in all branches of analytical chemistry. BrJAC is an open access journal which does not charge authors an article processing fee. Scope BrJAC is dedicated to professionals involved in science, technology and innovation projects in the area of analytical chemistry at universities, research centers and in industry. BrJAC publishes original, unpublished scientific articles and technical notes that are peer reviewed in the double-blind way. In addition, it publishes reviews, interviews, points of view, letters, sponsor reports, and features related to analytical chemistry. Manuscripts submitted for publication in BrJAC, either from universities, research centers, industry or any other public or private institution, cannot have been previously published or be currently submitted for publication in another journal. For manuscript preparation and submission, please see the Guidelines for the Authors section at the end of this edition. When submitting their manuscript for publication, the authors agree that the copyright will become the property of the Brazilian Journal of Analytical Chemistry, if and when accepted for publication. Published by Visão Fokka Communication Agency Publisher Lilian Freitas MTB: 0076693/ SP lilian.freitas@visaofokka.com.br Advertisement Luciene Campos luciene.campos@visaofokka.com.br ISSN 2179-3425 printed www.brjac.com.br
Editorial Assistant Silvana Odete Pisani brjac@brjac.com.br Art Director Adriana Garcia WebMaster Daniel Letieri
ISSN 2179-3433 digital Like BrJAC on Facebook: https://www.facebook.com/brjachem/
BrJAC is covered in the Clarivate Analytics Emerging Sources Citation Index Av. Washington Luiz, 4300 - Bloco G - 43 Campinas - SP - Brazil Zip Code 13042-105
BrJAC is associated to the Brazilian Association of Scientific Editors
+55 (19) 98322-7040 +55 (19) 99817-0405 contato@visaofokka.com.br www.visaofokka.com.br
Editorial Board Editor-in-Chief Lauro Tatsuo Kubota Full Professor / Institute of Chemistry - University of Campinas - Campinas, SP, BR Associate Editors Cristina Maria Schuch Analytical Department Manager / Solvay Research & Innovation Center - Paris, FR Elcio Cruz de Oliveira Technical Consultant / Technol. Mngmt. - Petrobras Transporte S.A. and Aggregate Professor / Post-graduate Program in Metrology - Pontifical Catholic University, Rio de Janeiro, RJ, BR Fernando Vitorino da Silva Chemistry Laboratory Manager - Nestle Quality Assurance Center - São Paulo, SP, BR Marco Aurélio Zezzi Arruda Full Professor / Institute of Chemistry - University of Campinas - Campinas, SP, BR Pedro Vitoriano Oliveira Full Professor / Institute of Chemistry - University of São Paulo - São Paulo, SP, BR Renato Zanella Full Professor / Dept. of Chemistry - Federal University of Santa Maria - RS, BR Advisory Board Adriano Otávio Maldaner Criminal Expert / Forensic Chemistry Service - National Institute of Criminalistics - Brazilian Federal Police – Brasília, DF, BR Auro Atsushi Tanaka Full Professor / Dept. of Chemistry - Federal University of Maranhão, São Luís, MA, BR Carlos Roberto dos Santos President of CETESB - Environmental Company of São Paulo State, São Paulo, SP, BR Gisela de Aragão Umbuzeiro Professor / Technology School - University of Campinas - Campinas, SP, BR Isabel Cristina Sales Fontes Jardim Full Professor / Institute of Chemistry, University of Campinas, Campinas, SP, BR Janusz Pawliszyn Professor / Department of Chemistry - University of Waterloo, Ontario, Canada Joaquim de Araújo Nóbrega Full Professor / Dept. of Chemistry - Federal University of São Carlos - São Carlos, SP, BR José Anchieta Gomes Neto Associate Professor / São Paulo State University (UNESP), Institute of Chemistry, Araraquara, SP, BR José Dos Santos Malta Junior Pre-formulation Lab. Manager / EMS / NC Group – Hortolandia, SP, BR Luiz Rogerio M. Silva Quality Assurance Associate Director / EISAI Lab. – São Paulo, SP, BR Márcio das Virgens Rebouças Process & Technology Manager – GranBio Research Center - Campinas, SP, BR Marcos Nogueira Eberlin Full Professor / Institute of Chemistry - University of Campinas - Campinas, SP, BR Maria das Graças Andrade Korn Full Professor / Institute of Chemistry - Federal University of Bahia - Salvador, BA, BR Ricardo Erthal Santelli Full Professor / Institute of Chemistry - Federal University of Rio de Janeiro, RJ, BR
Br. J. Anal. Chem., 2018, 5 (18)
Contents Editorial Where does the Measurement Process begin and end in Analytical Chemistry? Interview Professor Norberto Peporine Lopes, who has a very prominent academic career, recently spoke with BrJAC
1-1
2-5
Points of View Trends in the Environmental Analytical Chemistry
6-7
Analytical Chemistry: Atmospheric Particulate Matter and Environment
8-9
Letters Challenges in Environmental Analytical Chemistry
10-10
Leading the organization of the 5th EspeQBrasil
11-11
Review An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
12-27
Articles Development of an analytical methodology for chemical profile of cocaine seized in Rio de Janeiro Sensitive Voltammetric Method for Piroxicam Determination in Pharmaceutical, Urine and Tap Water Samples Using an Anodically Pretreated Boron-Doped Diamond Electrode
28-39 40-50
Features 5th EspeQBrasil discussed the prominent role of Chemical Speciation within Analytical Chemistry
51-52
Pittcon 2018 Presented the Latest Innovations in Laboratory Instrumentation
53-57
Sponsor Reports Determination of mercury in animal feed by direct mercury analysis (DMA): a simple analysis
59-61
Accurate Determination of Arsenic and Selenium in Environmental Samples using the Thermo Scientific iCAP TQ ICP-MS
62-67
Optimized GC-MS Solution for Semivolatiles (SVOC) Analysis in Environmental Samples in Compliance with the U.S. EPA Method 8270D
68-80
Releases DMA-80 - The most successful Hg analyzer in the market
82-82 82
BrJAC is starting a partnership with SelectScience®
84-84
Redefining ICP-MS triple quadrupole technology with unique ease of use Unstoppable
86-86
GC-MS Routine Analysis
88-88
CHROMacademy helps increase your knowledge, efficiency and productivity in the lab
90-90
Notices of Books
91-91
Periodicals & Websites
92-92
Events
93-94
Author's Guidelines
95-98
Br. J. Anal. Chem., 2018, 5 (18), 1-1 DOI: 10.30744/brjac.2179-3425.2018.5.18.1-1
Editorial
Download
Where Does the Measurement Process Begin and End in Analytical Chemistry? Elcio Cruz de Oliveira Technical Consultant at Petrobras Transporte S.A. – TRANSPETRO Rio de Janeiro, RJ, Brazil, elciooliveira@petrobras.com.br Professor of the Postgraduate Program in Metrology, Metrology for Quality and Innovation at the Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil, elciooliveira@puc-rio.br Analytical Chemistry can be afforded different descriptions in relation to four distinct time periods: the time period prior to the existence of microcomputers, up to the 1970s; the time period encompassing the early stages of the use of microcomputers in the 1980s; during the exponential growth of microcomputers in the 1990s; and finally, the current century, with passive and active applications. As time progressed, classical Chemistry has detrimentally lost ground to instrumental analysis. Compared to the first time I entered a laboratory, it is now a fascinating new reality! In light of this paradigm shift, I have noticed that some chemists suppose that the measurement process begins when a technician inserts a sample into an instrument, and that the process ends when the result is issued. This supposition is understandable when the current literature, itself, offers two distinctions: measurement processes and measuring equipment. Indeed, chemical measurement processes can be divided into discrete steps: identification and definition of the measurand (first conceptual step); sampling (start of the experiment's measurement process); use of reference materials and certified reference materials; sample preparation; qualified labor and instrumental measurement system; and, critical analysis of the result. The last step includes uncertainty measurement against specifications or statutory limits, and, the end of the measurement process. From my point of view, sampling and sample preparation are the particularities that most distinguish the chemical measurement process from the physical one. However, since the sampling process is not always recognized as a critical step, inexperienced professionals perform it carelessly; despite the fact that this step may significantly interfere with the analytical result. It has been convenient to assert the sampling target as a representative sample of the population, but not to describe and express the relevance of the sample. Considering the measurement uncertainty as a quality parameter, depending on the matrix and the analyte,the sampling uncertainty is dominant in comparison to the analytical uncertainty. Studies of environmental systems (e.g., soil, water, air, waste, etc.) are better examples for ratifying this assumption. In these matrices, the spatial and/or temporal heterogeneity of the analyte in the sampling target can be very relevant. Analytical chemists must get out of their comfort zones, shed light on the sampling process and better understand the entire measurement process. I suppose that it is already clear where the measurement process begins and ends! I conclude with my own proposal for a definition of the measurement process in Analytical Chemistry: ensure a survey of all input quantities that contribute significantly to the quantification of the analyte, thus guaranteeing that the analyzed sample represents perfectly the properties of interest in the parent population; it could be useful in the case of a situation in dispute.
1
Br. J. Anal. Chem., 2018, 5 (18), 2-5 DOI: 10.30744/brjac.2179-3425.2018.5.18.2-5
Interview
Download
Professor Norberto Peporine Lopes, who has a very prominent academic career, recently spoke with BrJAC Norberto Peporine Lopes Full Professor at the Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, SP, BR npelopes@fcfrp.usp.br
Professor Norberto Peporine Lopes is a pharmacist with a Master's degree in Pharmaceutical Sciences and a PhD in Chemistry from the University of São Paulo (USP). Currently, Norberto is a Full Professor of Organic Chemistry at the Faculty of Pharmaceutical Sciences of Ribeirão Preto (FCFRP-USP). He is also the coordinator of the Research Center for Natural and Synthetic Products and the Center for Mass Spectrometry of Organic Micromolecules (CEMMO). During his career, he has developed research abroad, in three long-term specializations at the Universities of Tübingem (Germany), Washington State (United States) and Bristol (United Kingdom). In 2000, he undertook postdoctoral training in mass spectrometry of natural products at the University of Cambridge (United Kingdom). From 2009 to date, he has held into a program of a Guest Professor in Mass Spectrometry at the Department of Food Chemistry of the University of Muenster (Germany). Norberto is a full member of the Brazilian Academy of Sciences, in addition to the Brazilian Society of Pharmaceutical Sciences, the Brazilian Mass Spectrometry Society (BrMASS), the Brazilian Chemical Society (SBQ), the Brazilian Society of Pharmacognosy and is a Fellow of the Royal Chemical Society. Among these societies, he holds the position of President of the Brazilian Chemical Society and is a member of the BrMASS Board. He has published more than 350 scientific articles and received eight awards, in particular, the BrMASS and Fernando Galembeck's SBQ Medals. When he received the BrMASS medal, he was surprised to be recognized by the congress: "I was surprised, I was very happy of course, but I was surprised because when we created this honor in society, it had as its main focus to honor the pioneering researchers," Norberto told the Web portal “Visão Ciência”. The research interests of the Professor are centered on natural product chemistry and mass spectrometry in both basic chemical aspects (gas phase reaction mechanism studies) and their biological and ecological importance. More recently, he has dedicated himself to contributing to the understanding of the phase one metabolism of natural xenobiotics. Nowadays, he is the coordinator of a thematic FAPESP project on the subject and has worked with passion in the field of chemical ecology since the beginning of his career. His laboratory, therefore, has special interest in all aspects of the discovery of new natural products and has a strong track record for innovation. Five spins off were born from his group, with most of them being created by former postdoctoral researchers. When was your first contact with chemistry? Did you have any influencer, for example, a teacher? Since childhood I have been very curious about issues related to nature. Over the years, I joined my father on his field trips and became familiarized in the phytochemical area, since my father and uncle were both USP professors. My contact with botanists and chemists influenced me significantly and I can say that I grew up breathing in natural product chemistry. 2
Interview When did you decide to begin a career in chemistry? What motivated you? How was the beginning of your career? By the mid-1980s, the issues surrounding genetics were boiling and the growing fascination with this area made me choose a subject where I could get in touch with the different focuses of biology and chemistry. Thus, in 1986, I joined the Faculty of Pharmaceutical Sciences of Ribeirão Preto (USP), where I took internships and participated in scientific initiation programs in biological fields. After working as a FAPESP fellow in a project on the regulatory mechanisms of glucose metabolism, the opportunity arose to work at the University of Tübingen in Germany in a project in plant cell culture of the Digitalis species. Despite my intimate contact with plants, as a result of the phytochemical work carried out by my father and uncle all my life, I had never thought of working with them, but the fascination was so great that I decided By the mid-1980s, the issues surrounding genetics were boiling and the growing to carry out my work in the German laboratory with fascination with this area made me choose phytochemistry of these cells. Since that point, I a subject where I could get in touch with returned to my family origins and have never stopped the different focuses of biology and chemistry. working on natural product chemistry and related topics. What are your lines of research? What jobs are you currently working on? Have you published many scientific papers? Would you highlight any? We are currently working with the application of mass spectrometry in the analysis of natural products. In our group, we investigate the chemistry of animals, plants and microorganisms, with the aim of understanding secondary metabolite functions. In these protocols, we apply mass spectrometry as the main tool for the metabolomics and for the imaging studies. With regard to scientific publications, we have been able to significantly increase both quantitative and qualitative production in the last decade, which I believe is the current challenge of Brazilian Science. In this sense, I believe that for the metric indicators of the agencies, the articles that we publish in journals such as Nature Biotechnology, Chemical Society Reviews, PNAS, Nature Ecology and Evolution would be the most outstanding. However, I think the two most important contributions were the compilation of the fragmentation reactions in ESI-MS/MS systems and the characterization of caramboxin. The work published in the Natural Products Report organized and systematized these reactions in a pioneering way and today it is used as courseware of structural determination applying mass spectrometry, so it has had a significant impact on the training of students, something we strongly consider. The second was a cover work for Angewandte Chemie, in which the strongest point is the social impact. The letters and emails my co-workers and I have received about lives that have been saved based on this article cannot be described here. How do you keep informed about the progress of chemistry research? What is your opinion regarding the current progress of research in chemistry in Brazil? What are the latest advances and challenges in scientific research in Brazil? My position on the SBQ board allows me to follow what is happening with Chemistry, both at national and international levels. One point that has attracted our attention is the gradual increase in the scientific production of chemistry in Brazil and mainly the increase in the number of articles signed by Brazilians in the main periodicals of the area. I think the biggest challenge today is to convert scientific data into innovation in the productive sector, to become more active in the development of new products. It is true that the number of academic spins off has grown significantly and the chemistry is also contributing in this scenario, but I believe that with the publication of the I think that one of the greatest social impacts "Legal Framework of Science, Technology and of current analytical chemistry is the doctorate Innovation" (Law nº 13.243 / 2016, published on 08/02/ of Dr. Lívia Eberlin with Prof. Cooks. Bringing 2018), we will have an even greater participation. the mass equipment into the surgical room in the hospitals will strongly impact the mass spectrometry field. 3
Interview In your opinion, what have been the most important achievements in the world of analytic research recently? What were the landmarks? We could discuss different advances, but drawing more focus to the Brazilians, I think that one of the greatest social impacts of current analytical chemistry is the doctorate of Dr. Lívia Eberlin with Prof. Cooks. Bringing the mass equipment into the surgical room in the hospitals will strongly impact the mass spectrometry field. Another great advance has been the ability to generate an ever-increasing collection of analytical data, and with the new computational tools, we start working with metadata. For nearly 20 years, computational chemistry and biology have already been recognized as independent research fields, merging a set of computational, statistical, mathematical and other fields of research involved in data processing that are generated by analytical chemists. According to the director of the Stanford University Biomedical Computing Training Program in Palo Alto, California, Prof. Russ Altman, the market with lucrative salaries is absorbing metadata scientists as they graduate. In an article written for the journal Science in the section dedicated to professional careers, Prof. Russ Altman points out that in traditional training, chemists and biopharmacologists are trained for smallscale analysis and that the new challenge will be to extend the logic of scale, which was a major step forward for the decade. There are several scientific meetings on chemistry in Brazil and around the world. To you, how important are these meetings for the area? How do you see the development of national scientific chemistry meetings in Brazil? Conferences are important events for professional updating and also for maintaining networks. As in any field, networking is fundamental to broaden collaborations and discuss new ideas. However, we can nowadays find a large number of events with commercial purposes all over the world. It is important to analyze carefully, as it has become a good business model that can also be seen with the scientific journals, aiming only for profit.
Prof. Norberto Peporine Lopes presenting a lecture at IUPAC World Congress - 2017
In Brazil, we have a certain degree of spraying, with many very specialized congresses for specific subjects. As a result, we can see a decrease in the participation of researchers in larger meetings and it can become a problem. In the US, ACS meetings are one of the largest events in the American scientific community. This forum discusses policies, strategies and the main scientific advances of all sub-areas of chemistry. This gives strength to this community and helps maintain sovereignty in internal affairs over chemistry. In Brazil, it seems that we are worrying much more about the specialization and it may have an impact on the future. Moreover, young Brazilian researchers are not absorbing the fundamental concept of participating in a scientific society, thinking only of the meeting itself. In my opinion, this is another aggravating point. You have already received awards. What is it like to receive this kind of recognition? What is the importance of these awards in the development of science and new technologies? The vast majority of us have a degree of vanity. Therefore, receiving a prize is always a great joy, but I believe it is very important to analyze the honor in an easy way. What makes us productive is to believe that every day we have something new to learn and grow. Thus, in my opinion the premiums are always important, but they cannot be met with an increased dose of self-confidence. Recognizing, honoring 4
Interview and rewarding people is a healthy act, especially when performed in life. As I mentioned before, every form of stimulation can advance us further and generate new knowledge and technologies. For you, what is the importance of the support of the research funding agencies (Coordination for the Improvement of Higher Education Personnel - CAPES, São Paulo Research Foundation– FAPESP and so on) for the scientific development of Brazil? By definition, the development agency is the institution with the main objective of financing capital and costing for projects foreseen in scientific and innovation development programs. Therefore, without the existence of development agencies there would be no research in Brazil. In the last decade, the agencies have started to act more actively in innovation and today there are several companies of national capital that were born in the universities and only reached the market by the initial incentive of these agencies. Another important point is that agencies, such as CAPES, act in the evaluation system. I am not here to state whether the evaluation model is correct or not, but just to reinforce that any program or system needs to be evaluated to evolve. Without evaluation, we have the characteristic of accommodation that is bad for the development of science and technology. How is a career in the field of analytical chemistry? What advice would you give to a newcomer in this area? Doing just what is expected of the person will usually produce a good technician but will hardly result in a professional that will make a difference in the market.
My parents taught me to always look for the best. Doing just what is expected of the person will usually produce a good technician but will hardly result in a professional that will make a difference in the market. My main advice is to analyze your vocation well and make sure that you really enjoy research and want to take all the risks that this option will bring. Taken that decision, dedicate yourself as much as you can, especially in reading and studying, something that we are reducing day by day by the current lifestyle.
With the current scenario, how is the labor market in analytical chemistry in Brazil? What differs from working abroad? Brazil is going through a very complicated economic and social moment. Previous models of postgraduate studies with a view to teaching careers are well established and there should be no further expansion in the coming years. Therefore, graduate programs in analytical chemistry should shift the focus to the absorption of this highly qualified human material by the productive sector. In our group, we have several experiences of alumni today occupying important positions in pharmaceutical companies and some have been brave and set out to create their own business models, something that I view with good eyes. Abroad, the productive sector absorbs a greater quantity of analytical chemists and with better salaries. I believe this is the big difference, because with a greater supply in the productive sector, the impoundment of positions in academia diminishes.
5
Br. J. Anal. Chem., 2018, 5 (18), 6-7 DOI: 10.30744/brjac.2179-3425.2018.5.18.6-7
Point of View
Download
Trends in Environmental Analytical Chemistry Cassiana C. Montagner Assistant Professor Department of Analytical Chemistry, Institute of Chemistry, University of Campinas (UNICAMP), Brazil montagner@iqm.unicamp.br
Environmental Science is a broad science that studies the complex interactions among biota and humans with aquatic, terrestrial and atmospheric environments, as well as the effects caused by anthropogenic activities on these natural processes. It is an interdisciplinary science that involves chemistry, biology, engineering, medicine, government and others aiming to understand the changes that have occurred in the environment, from a small compartment to a global scenario responding to the challenges of the planet. Environmental Chemistry studies the sources, reactions, transport and fates of chemical species in water, soil, air and living organisms. There is a strong relationship of this science with Analytical Chemistry. In fact, Environmental Chemistry studies in Brazil have developed strictly related to the Analytical Chemistry according to the Brazilian Chemical Society (SBQ) [1]. One of the major challenges of Environmental Chemistry is the identification and quantification of specific pollutants in the environment and for that, the development of analytical methods, tools for sampling and monitoring are needed to evaluate treatments and abatement options of contaminants or to monitor the presence of them in the environment. During the last century, great attention was given to contaminants such as gases, metals and organic compounds in ppm or ppb levels. Classical analytical tools have been used along with instrumental analyses to measure these contaminants at such concentrations with high confidence and low cost. However, since the beginning of this century chemists have become deeply involved in the investigation of environmental problems related of the presence of contaminants in concentrations around parts per trillion or less. This is because the ecotoxicologists found that at such low concentrations several contaminants were able to cause adverse effects in the chronic exposed biota including humans. Aware of these new research demands, analytical chemists have been working hard to develop new tools or to improve the sensitivity and detectability of the analytical instruments. In fact, there was a great improvement in analytical technologies for sampling, sample preparation and detection equipment. The challenge now is to concentrate the contaminants present at trace levels in the complex samples, remove the interferences present in the environmental matrices and transfer the target compounds to the appropriate solvent or environment to be determined by the appropriate analytical tool. Considering for example, the current research involving emerging contaminants (such as pharmaceuticals and personal care products, pesticides, hormones, industrial compounds, disinfection by products, microplastics, nanomaterials and others) in water the aim of the environmental analytical chemistry is to develop and validate analytical methods able to identify and quantify target or un-known compounds (non target) with appropriated detectability to achieve the concentrations needed by the ecotoxicologists. Because the ecotoxicologists dilute the contaminants until they find no adverse effects, sometimes the safe concentrations are much lower than the ones analytical chemists can determine.
6
Point of view Chemists are responsible for measure the concentrations and the biologists are responsible for defining safe environmental concentrations for the several uses of the water and soil. Ecotoxicology in fact is the science where biologists and chemists become what we call ecotoxicologists. There is no ecotoxicologist that can survive without expanding their knowledge to outside his comfort zone, exploring new areas and learning how to solve problems in complex situations. The main objective of ecotoxicology is to do risk assessment of a desired scenario and for that exposure evaluation (performed by chemists) along with hazard evaluation (performed by biologists) are the key elements. In the environmental chemistry area some challenges are presented. To evaluate environmental exposure it is necessary to plan ahead and define a complete analytical method, considering since when, where, how many times and which kind of sampling is appropriate as well as define which is the best sample preparation protocol considering the physical-chemical proprieties of the contaminants of interest and the environmental compartment that will be studied, and of course, no less important, the instrumental tools that will be applied in the identification and quantification of the target compounds. Therefore, currently the ecotoxicological risk assessment is the key to minimize anthropogenic environmental impacts and environmental analytical chemistry is the key of this process.
1.Canela, M. C.; Fostier, A. H.; Grassi, M. T. Quim. Nova, 2017, 40, pp 634-642.
7
Br. J. Anal. Chem., 2018, 5 (18), 8-9 DOI: 10.30744/brjac.2179-3425.2018.5.18.8-9
Point of View
Download
Analytical Chemistry: Atmospheric Particulate Matter and Environment Júlio César José da Silva Associate Professor Baccan Group of Analytical Chemistry Chemistry Department, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil. julio.silva@ufjf.edu.br
I would like to thank the Brazilian Journal of Analytical Chemistry (BrJAC) for the invitation to contribute my point of view on atmospheric pollution, an important topic in environmental analytical chemistry. Atmospheric pollution has been an area of interest and concern throughout the years due to its harmful effects on agriculture, forests, buildings, works of art, and human health. Atmospheric pollution can occur directly (inhalation or ingestion) or indirectly (contamination of hydric resources, food, or soil), and is composed of atmospheric aerosol that is related to the emission source (anthropogenic or not). Atmospheric particulate matter (APM) can be present in the atmosphere in addition to gases. In urban environments, APM is mostly found as inhalable particles with aerodynamic diameters smaller than 10 micrometers (PM10) and as respirable particles (PM2.5 or smaller). The chemical characterization of APM and the investigation of its effects on the environment and human health requires, in my opinion, a multidisciplinary approach involving various areas of science, such as geosciences, health sciences, engineering, architecture and urbanism, physics, and chemistry. In this context, Analytical Chemistry has a fundamental role, including the development of sample preparation methods and the identification, quantification, and chemical speciation of trace elements (adverse effects on human health) and black carbon analysis (climate change and mortality due to respiratory diseases). Analytical Chemistry also involves the analysis of organic compounds such as polycyclic aromatic hydrocarbons (PAHs), the investigation of the bioaccessibility of essential and toxic species (risk assessment), the evaluation of meteorological influences compared to concentration/dispersion of particulate matter, and the application of receptor models (identifying and quantifying emission sources of particulates). In addition, Analytical Chemistry contributes to studies involving climate change (the particulate matter influences the radioactive balance and cloud formation; therefore, acting as an agent in climate change). Finally, Analytical Chemistry includes the investigation of internal atmospheres (indoor), such as classrooms, recreation areas, offices, automobiles, tunnels, parking lots, and bus stations (where concentrations of pollutants are often high). Analytical Chemistry can also help with the correlation of atmospheric pollution with the deleterious effects of cigarettes (cancer), the interactions between species in the soil, atmosphere, and water bodies, and the study of atmospheric pollution at regions affected by mining-metallurgical activities. Furthermore, the geosciences area is of fundamental importance for the comprehension of the obtained results and their interactions with the environment. In the specific case of Juiz de Fora (MG), the partnership between the Chemistry and Geosciences Departments of the Federal University of Juiz de Fora (DEGEO-UFJF) allowed for a better and critical interpretation of the meteorological data extracted from the meteorological station of UFJF.
8
Point of view In conclusion, it is not an overstatement to say that Analytical Chemistry is of great importance to studies related to atmospheric pollution. The diverse origins of this type of matrix (its composition depends on emission sources, such as biomass burning, vehicular emissions, and industrial emissions, etc.) and the complex nature of its interactions indicates an imperative demand for the development of new analytical strategies to overcome the challenges of atmospheric analyses, as discussed by Prof. Dr. Daniel Borges (DQ-UFSC) [1] in the special number of BrJAC dedicated to 17th Brazilian Meeting on Analytical Chemistry (ENQA). I would like to thank Professor CĂĄssia C. M. Ferreira (DEGEO-UFJF), Lilian L. R. Silva (DQ-UFJF), Aparecida M. S. Mimura (PhD, DQ-UFJF), and Ă‚ngela M. F. O. Lourdes (PhD student, DQ-UFJF) for reading the text. 1.Borges, D. L. G. Analytical Chemistry in Brazil: Working at the frontier. Br. J. Anal. Chem., 2014, 3 (12), p. X.
9
Br. J. Anal. Chem., 2018, 5 (18), 10-10 DOI: 10.30744/brjac.2179-3425.2018.5.18.10-10
Letter
Download
Challenges in Environmental Analytical Chemistry Claudia Carvalhinho Windmoeller Associate Professor Institute of Exact Sciences, Chemistry Department, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil claudiaufmg@hotmail.com
The world has already known and accepted the connection between environmental problems in certain parts of the planet, such as the Arctic, Antarctica and the Amazon and its effects in other regions of the globe. Knowledge that generates actions and decision making, including mitigation, certainly depends on technical data and therefore information found by various areas, especially by Environmental Analytical Chemistry. Data are often tied to legislation, which prompts analytical chemistry to seek new methodologies with better detection limits that can be used in routine laboratories or the ones that bring information far beyond quantification, such as chemical speciation or exactly where the "contaminant" is found in the matrix. Possible methodologies could involve faster processes, the use of fewer reagents or none, the use of a smaller amount of sample and finally generate a little waste. The requirement for more detailed analytical validation of methodologies for pollutant quantification is also, or at least should be, well known since the consequences related to the data and its interpretations can generate an immediate social and even forensic impact. Although the scientific community has done much, there are innovation challenges in analytical environmental chemistry. Some demands are vital so that the technical information can contribute in a more effective way for the construction of biogeochemical models increasingly closer to the real conditions found in the environment. These matters highlight new sampling technologies, including remote metering, in-situ measurement, continuous monitoring, the use of drones, or even allowing the chemical speciation of elements in trace amounts, new methodologies of direct analysis of environmental samples and development of modeling software. It is intriguing that these models, supported by mathematical and statistics tools, can be applied in predictions of environmental conditions not yet identified. Innovations in the field of Environmental Analytical Chemistry require, in most cases, interdisciplinary knowledge. For instance, the development of methodologies of speciation in certain biological matrices needs a prior knowledge of possible metabolic processes. On the other hand, development of soil, water or air sampling devices requires knowledge of hydrodynamics or relief of possible sites to be sampled. Still development of new software requires the largest amount of measurable information related to the environment under study, such as temperature, wind direction, all biotic events that need to be considered in the model, among others. The interdisciplinarity is one of the greatest challenges because the most relevant information cannot always be found in written works, it requires many times a careful evaluaion of specific field conditions which can influence the development that is desired. Finally, it is expected that an expansion of Environmental Analytical Chemistry contributes to the discussions on environmental themes become increasingly clearer in order to bring about changes in social behaviors that lead to a new mentality in the relationship between man and the environment.
10
Br. J. Anal. Chem., 2018, 5 (18), 11-11 DOI: 10.30744/brjac.2179-3425.2018.5.18.11-11
Letter
Download
Leading the organization of the 5th EspeQBrasil
Amauri Antonio Menegário, PhD CNPq Researcher Level III Coordinator of the Center for Environmental Studies at the São Paulo State University (CEA-UNESP), SP, Brazil amenega@rc.unesp.br
It is very frequent I say to close friends: having a child is very expensive, but, the “money” expended on my children was the best investment of my live. This phrase can be adapted when you are organizing a meeting that you see was born and growing. I feel the EspeQBrasil is like a son to me. When leading the organization of the 5th EspeQBrasil, I looked for its growth at least in four aspects: size, quality, scope and evolution of the meeting. I really believe that the EspeQBrasil should not be restricted to just chemical fractionation or speciation analysis. EspeQBrasil is a meeting to produce news in science from the development of analytical and environmental chemistry by joining peoples from different areas. A meeting where the real demand and approaches for new questions come to light. This position makes me more apprehensive, was very hard and time consuming or, using a single word, it was very expensive. th Nonetheless, the money expended on organizing the 5 EspeQBrasil resulted in a real mark in my career. Similar as my wife was essential for having and for growing up my children, my research group (please see their names at https://www2.unesp.br/portal#!/cea/home/espeqbrasil2017/) was essential for organizing the 5th EspeQBrasil. Like a wife, the hard part of the work was given to my research group. They were th involved in everything: I just delegate work and they take care of the 5 EspeQ. Similar to the wife's life they also have double burden. Also, I couldn't forget the friends, the CEA/UNESP (and its staff), companies and the agencies that provide the financial support to 5th EspeQBrasil.
5th EspeQBrasil Scientific Committee
Finally, I would like to point out the South American-UK Agri-Industrial Waste-to-Land Challenge th Hub workshop (organized by Prof. Paul N. Williams) that ran alongside the 5 EspeQ Brasil and brought peoples from different areas and countries to our Brazilian meeting. We made mistakes, we had surprises (bad and great ones), we fought among ourselves and we tirelessly work to the point of exhaustion. However, we had a meeting that we love and I suppose where th the real demand and approaches for news analytical and environmental question comes to light: 5 EspeQBrasil. 11
Br. J. Anal. Chem., 2018, 5 (18), 12-27 DOI: 10.30744/brjac.2179-3425.2018.5.18.12-27
Review
Download
An Innovative and Integrated Food Research Approach: Spectroscopy Applications to Milk and a Case Study of a Milk-Based Dish Spectroscopy Applications to Milk and Derived Products 1*
2
1
1
Alessandra Durazzo , Johannes Kiefer , Massimo Lucarini , Stefania Marconi , Silvia Lisciani1, Emanuela Camilli1, Loretta Gambelli1, Paolo Gabrielli1, Altero Aguzzi1, Enrico Finotti1, and Luisa Marletta1 1 Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria - Centro di ricerca (CREA) Alimenti e Nutrizione, Via Ardeatina 546, 00178 Roma, IT 2 Technische Thermodynamik and MAPEX Center for Materials and Processes, Universität Bremen, Badgasteiner Str. 1, 28359 Bremen, DE An integrated and multidisciplinary system of analysis, using innovative and emerging technologies, combined with chemometric data evaluation, is becoming a valuable tool for food analysis. The main lines of this approach and the exploitation of innovative possibilities applied to milk products are reviewed and discussed. Special attention is paid to spectroscopic techniques combined with multivariate statistical data analysis. Moreover, a case study of a milk-based dish is reported: the IR spectroscopic characterization and assignment of the main bands of Béchamel sauce is shown. This can serve as a basis for developing multivariate calibration models for useful applications in order to collect information having specific required characteristics, e.g. for discrimination of products and the investigation of fraud. The main perspective is the increased awareness of the importance of sharing data and the creation of an integrated system for calibration and standardization of milk product spectra in the Multicentre Research Network. It aims at making the analysis faster to ensure economic and health safety in a global context. Keywords: Integrated Food Research; Chemometrics; New markers; Milk; Béchamel sauce. Key Points and Descriptors of a Modern, Integrated and Innovative Approach of Food Research An integrated and multidisciplinary system of analysis is becoming a valuable tool to analyze and study food, taking into account the various aspects of food quality and composition by employing innovative and emerging technologies. Such a multi-technique approach to food research enables utilizing all the resources of quality, safety and traceability in food systems. A lot of advanced and emerging analytical techniques such as infrared (IR) spectroscopy, multi-elemental analysis, isotopic ratio mass spectrometry have been applied to verify different items, i.e. origin and provenance of foods and authentication concerning the food system [1,2]. The “Integrated Approach” is the key of modern food research and the innovative challenge for analyzing and modelling agro-food systems in their totality. The experimental methodology must be complemented by suitable data analysis tools. Chemometrics is defined as the relevant discipline to extract the right information from chemical experimental data using mathematical and statistical methods. Nowadays, a large quantity of analytical data is produced from a simple experiment. To handle these data different statistical approaches have been developed and applied to achieve a comprehensive and meaningful analysis [3-5]. Generally, the application of statistical methods in food science allows to highlight effective trends, study and investigate relationships and make conclusions from experimental data [6]. *alessandra.durazzo@crea.gov.it http://orcid.org/0000-0002-7747-9107
12
An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
Review
The combined uses of experimental data lead to a comprehensive user database for multivariate statistical analysis, a valid complex tool for the development of models and applications of data study: starting from data analysis, through the extraction of qualitative and quantitative information, and possibly leading to enhanced food research in various directions and boost knowledge. Indeed, the multivariate statistical approach applied to the combined chemical data i.e. physicochemical, spectral, multi-elemental, isotopic parameters, allows the evaluation of qualitative, safety and nutraceutical aspects as well as the development and definition of new quality and safety controls, e.g. through the identification of suitable biomarkers. The following preliminary plan helps to define the principal lines of this approach and the tasks involved: - Planning and designing experiments in food science: due to the fact that food products are highly complex systems containing hundreds of chemical species, there is a need for analytical technology that can deal with this complexity. - Conducting experiments and applying experimental methods to get data containing information about food composition and state. - Processing analytical data and understanding the linkage and inter-relationship among various measurements. - Using computational methods for data evaluation to extract meaningful information about food composition and state. - Combining and associating individual parameters to cover different aspects and features of foods. - Connecting User Databases. - Using and taking advantage of Chemometrics. - Producing and Making use of Model Development and Applications. - Identifying new markers. - Selecting management tools (farm, food and health). There is a high demand for new rapid and green analytical methodologies that allow the direct analysis of a sample. The list of potential experimental techniques includes fluorescence, near infrared (NIR), mid infrared (MIR), and nuclear magnetic resonance (NMR) spectroscopies in combination with multivariate data analysis methods. Pooling and combining these methods could be considered as an emerging integrated tool in food research. The applications of spectroscopic techniques coupled with chemometric analysis [7] encompass qualitative and quantitative analysis, food classification, discrimination and authentication, as well as monitoring of contaminants and adulterants [8]. For these purposes, spectroscopic data should be collected and inserted as routine analysis in each food chain at different levels in order to construct a comprehensive library or database of spectra that can be linked and connected to give an Integrated User Database (IUD) of each food product. An Integrated Food Research Approach Combining IR Spectroscopy and Advanced Chemometrics Applied to Milk The implementation of standards and criteria of some aspects concerning food safety and quality as well as the ensuring of product authenticity represent the core issues in the dairy sector. The analysis of milk and other dairy products can be performed through advanced techniques including near- and midinfrared spectroscopy, mass spectrometry as well as chromatography, immune enzymatic assays, Polymerase Chain Reaction (PCR), and electrophoresis [8, 9]. The present study focuses on an integrated food research approach combining IR spectroscopy and advanced chemometrics applied to a milk product. The application of the multivariate data analysis for the quantification of dairy products has already been reported a couple of decades ago. This was coincident with the advent of new paradigms in analytical chemistry, environmental protection and workplace safety requirements, as well as the demand for food traceability and the added value of products thanks to the introduction of the protected designation of origin (PDO) [10]. Moreover, increasing labor cost and the availability of computational power promoted the rise of chemometrics in the entire food sector [11]. 13
Durazzo, A.; Kiefer, J.; Lucarini, M.; Marconi, S.; Lisciani, S.; Camilli, E.; Gambelli, L.; Gabrielli, P.; Aguzzi, A.; Finotti, E.; Marletta, L.
Review Article
As for nearly all analytical fields, dairy analysis began with univariate methodologies, which proved to be successful for working on the old paradigms; however, multivariate data analysis has gained wider acceptance during the last three decades. The success of chemometrics in this area stems from its ability to extract only the essential and relevant portions of a data set after filtering out noise or unnecessary information [4]. Additionally, chemometrics allows better quality controls. It is fast and eco-friendly, and it offers more information as well as an improved process understanding [12]. This section aims at reviewing the relevant literature on this topic, by giving an introduction to various chemometrics methods and an overview of their applications to milk. Chemometrics tools: description and outputs - Exploitation of possibilities Chemometrics quantitative methods can be classified in two general groups, first order methods and higher order methods. First order methods use a data vector for each sample as an input signal. This data vector can be provided by any analytical technique that is capable of giving non-scalar results for each sample. For example, this vector could be obtained by varying a parameter such as wavelength and recording intensity or absorbance values as function of the varied parameter like it is done in NIR, MIR, and UV-Vis spectroscopy. Another example of such a vector is a thermogram from DSC analysis, in which the temperature is varied. Overview of first and higher order methods The general working principle of first order methods is illustrated in Figure 1. Usually, calibration data from well-known samples are recorded and used to train the chemometric algorithm. Thereafter, data from unknown samples can be processed to determine the parameters of interest. Partial least squares (PLS) regression has become the golden standard in chemometrics applied to dairy due to its wide applicability and large availability of the algorithm on many software packages [13, 14]: mathematical [Matlab minitab, R], statistical [SAS, Excel], equipment [OPUS, Shimadzu,], chemometrics dedicated software [Unscrambler, SIMCA]).
Figure 1. General working principle of first order methods in milk derived products. Data flow and usual scopes.
PLS is a ''full-spectrum'' method, where compression of the data is made using both instrumental signals (X matrix) and analyte concentrations (y vector). The non-linear iterative partial least squares algorithm provides two types of loadings contained in the matrices W (weight loadings) and P (loadings). Both help to explain the maximum covariance among X (instrumental data) and Y (concentration data). The matrices W and P are used to find regression coefficients (r), and finally to predict the analyte concentration in an unknown sample. Like its ancestor, principal component regression (PCR) [15], PLS was used for the determination of chemical parameters [16]: total fat, protein, and carbohydrates were determined using PLS coupled to FTIR with dispersion lower than 0.1% in all cases. Additionally, an indirect parameter, i.e. as kcal/100 ml, was successfully accessed with the same pair. Another indirect measurement that deserves to be mentioned is the determination of the solid non-fat in raw milk using PLS-MIR [17]. The entire fatty acid profile of milk samples was determined using PLS-MIR regression powered by a genetic algorithm in the variable selection, carried out by the group of Ferrand [18]. 14
An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
Review
Other first-order methods based on natural computing methods are backpropagation artificial neural networks (ANN) [19]. ANNs are indicated to operate a non-linear mapping between an input and a target space. ANNs operate using a large number of simple parallel connected arithmetic units (neurons, Figure 2). Mathematically, a neuron can be defined as a non-linear, parameterized and bounded function (i.e. f(x) = 1/e∑wixi). The variables of the signal vector x (x1, x2 x3 x4,…, xn) are called "neuron inputs" and the calculated value of the function is called "neuron output" (ys). ANNs have a flexibility that makes them adaptable to different kinds of data structure, and liable to being custom-designed. In principle, ANNs have the same field of action as PLS. However, they are particularly suited to deal with highly non-linear problems, where the traditional statistical methods usually fail. On the other hand, they are prone to overfitting when the complexity of the relationship between input and output variables is low. As all first order methods, ANNs are capable of dealing with interferences, which are present in the calibration step. This feature is often referred to as the “first order advantage”. Support vector machines (SVM) are also supervised learning algorithms that analyze data used for regression analysis [20]. SVMs project a given data set into a higher-order mathematical space, where clear correlations between the observables and measurands are present [21].
Figure 2. General calculus of first order methods. Data flow for PLS and ANN. It the dairy sector, ANNs were used to determine the total protein content in yogurt using MIR data with an error during calibration about 7% [22]. In the other extreme, ANNs were used to model an automated biosensor for the quantification of a binary organophosphate mixture in milk using a highly non-linear electrochemical signal [23]. Less widespread are the “high order methods”, where data for a single sample are contained in a multidimensional array (a matrix). High order methods (HOMs) can perform determinations in the presence of interferences not taking into account the calibration step. This property is known as “the second-order advantage” and makes HOMs particularly attractive for applications to complex samples. In this context, parallel factor analysis (PARAFAC) and multivariate curve resolution coupled with alternating least squares (MCR-ALS) are the most used techniques and present an inherent second-order advantage. For PARAFAC and MCR-ALS, the calibration samples and test (unknown) samples are put together and are decomposed by the model. Consequently, the number of factors necessary to perform the regression model is determined at once. In theory, they are equal to the number of independent chemical species in the calibration samples and the unknown interferences in the test samples. PARAFAC assumes that the data array for a group of samples follows a trilinear model [24] (Bro, 1997), while MCR-ALS places second-order data for a group of samples adjacent to each other along a qualitative dimension (usually the time dimension). Furthermore, 15
Review
Durazzo, A.; Kiefer, J.; Lucarini, M.; Marconi, S.; Lisciani, S.; Camilli, E.; Gambelli, L.; Gabrielli, P.; Aguzzi, A.; Finotti, E.; Marletta, L.
it assumes that the augmented matrix follows a bilinear model [25]. For quantitative analysis, areas or amplitude of the sample profiles (in the augmented dimension) are computed, and used to build a pseudounivariate calibration graph. On the other hand, the PLS residual bi-linearization procedure (PLS-RBL) calibrates a PLS model, and assumes that the signals from the interference in the test sample follow a bilinear model. The analyte scores are produced by modeling the residuals of the fit of the test sample data array to the bilinear model, hence the name residual bi-linearization [26]. Morales et al. [27] reported an analytical procedure to determine sulfathiazole in milk by using molecular fluorescence spectroscopy and PARAFAC decomposition [27]. The use of the second order advantage avoided the need of fitting a new calibration model each time that the experimental conditions change. Tetracycline in whey milk was also determined by using PARAFAC and fluorescence [28]. Forchetti and Poppi [29] used MCR-ALSE on NIR hyperspectral imaging data to detect and quantify whey powder, starch, urea, and melamine as adulterants in milk powder. They achieved an LOD of the order of 0.05%. Finally, the quantification of melamine in milk samples was carried out applying PLS-RBL, PARAFAC and MCR-ALS to UV-Vis absorbance- measurements at varied pH value [30]. In this comparison, PLS-RBL PLS-RBL outperformed the other methods with superior mean recoveries and relative errors of prediction (100.1 ± 2.3%). Unsupervised Qualitative methods Unsupervised “classification”, often called clustering, occurs when the algorithm has no a priori knowledge of the groups present in the population and the samples have a set of features with unclear relationships with a class or category. The purpose of unsupervised methods is the discovery of groups of samples which have related features, to allow their separation into different classes. Principal Component Analysis (PCA) is the most widespread unsupervised tool in the field of food [31]. PCA is a technique used to reduce the dimensionality of a data set. It is primarily used as a display methodology in exploratory analysis. PCA involves calculating the eigenvalue decomposition of the covariance matrix, usually after data centering. Samples that are placed in the new space show closer positions when they have a strong relationship. On the other hand, Hierarchical Clustering Analysis (HCA) [32] allows to see grouping relations between the data. The successive hierarchical subdivisions provide an idea about the grouping criteria in a dendrogram. It is a tree-shape chart that organizes data into subcategories, which are divided to reach the desired level of detail. Brescia et al. [33] typified the geographical origin of buffalo milk and mozzarella cheese using data of high performance ion chromatography and inductively coupled plasma emission spectroscopy analyzed through PCA and HCA. They compared their results with those obtained by nuclear magnetic resonance and isotope ratio mass spectrometry, which was also evaluated through both multivariate technics. PCA was also applied to data from laser induced breakdown spectroscopy (LIBS) in order to detect milk adulteration with melamine. ANN was subsequently used to access the level of contamination in positive samples [34]. Self-organizing maps (SOM), also named Kohonen neural networks [35], provide a way of representing multidimensional data in a two-dimensional map. The map consists of components called neurons, which have defined positions and are associated with a weight vector of the same dimension as the input data vectors. The procedure for placing a sample from onto the new map is to find the neuron with minimum distance. The weight vector of this neuron (the winner-one) is corrected towards the object position. The procedure is iteratively repeated a number of times (named ages) pre-established by the user. To give an example, SOMs were used to analyze the profile of twelve PCBs (obtained by headspace solid-phase microextraction/gas chromatography electron capture detection) present in breast milk. The resulting data matched to general habits, breastfeeding and environmental conditions of the living place [36]. Factor analysis (FA) [37], Gaussian mixture models (GMM) and K-means [38], completed the commonly used unsupervised methods.
16
An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
Review
Supervised methods (Classification methods) Supervised methods are the true Classification methods, where the information about the belonging of each sample to a certain class is known. This knowledge is used for the algorithm to extract the model information, or assign a new sample to a class. Linear discriminant analysis (LDA), like PCA, is a linear feature reduction method. LDA method that focuses on finding optimal boundaries (parametric) between classes. LDA, the widely used supervised classification method, selects the space directions that achieve a maximum separation among the different classes and uses Euclidean distance to classify unknown samples [39]. LDA successfully recognizes the milk samples according to their thermal processing, i.e. pasteurized milk, sterilized milk, UHT fresh milk and recombined milk (UHT milk having milk powder), with 100% classification accuracy in a cross validation, based on fluorescence response 400–600 nm when samples were excited at 375 nm [40]. PLS-discriminant analysis (PLS-DA) is another linear parametric method, which carries out a PLS of a set Y of binary variables, 0 or 1 (when the sample belongs to the class), on a set X of predictor variables [41]. Back propagation neural network (ANN) and support vector machines (SVM) are the most frequently used analysis [42]. As in the case of PLS-DA, the algorithm makes a correlation among a binary variable when data is non-linearly distributed. The work of Rodriguez and co-workers [43] showed how PLS-DA can discriminate among powder milk samples with normal and low lactose. In a second step, the same algorithm was used to detect sample adulterated with maltodextrine [43]. PCA was used in the early step to check if separation of the groups was possible. Soft independent modelling of class analogy (SIMCA) puts more emphasis on similarity within a class than on discrimination among classes [44]. SIMCA considers each class separately and performs a PCA on each one, which leads to one model per class. An object is challenged to every class model and it is assigned to the class that produces the smallest residue during the prediction. SIMCA coupled to MIR spectroscopy was evaluated as a rapid method for the detection and quantification of anionic detergent (lissapol) in milk. The classification efficiency for test samples was recorded to be >93% [45]. SIMCA was also coupled to MIR spectroscopy for the detection of soymilk in cow-buffalo milk [46]. For completeness, Canonical Discriminant Analysis (CDA) [47] and extended canonical variate analysis (ECVA) [48] also belong to the linear supervised classification methods. Design of experiments Design of experiments (DOE) is used both to determine how factors or parameters affect the production process and to optimize the process in a laboratory or a plant. During the screening phase of DOE, it is determined which factors may significantly affect the response of the experiment. Plackett-Burman or factorial fractional analysis are the most suitable approaches to find the factors which significantly influence the response [49] running a minimum number of experiments. DOE was used to optimize the response [50], by finding factor values through a mathematical model. For this purpose, Factorial (Fractional Factorial), Central Composite, Box-Behnken and Mixture Models designs are the best choices to set off the objective and the planning of the experiment. The response surface (or space) for each variable to optimize could be calculated with multiple linear regression. The optimal value of the response in the surface generated by many responses could be calculated with Derringer's desirability function [51]. The work of Koc et al. [52] is a good example of DOE. The authors describe the optimization of whole milk powder processing variables [52]. DOE was used to design the experiments for collecting data that was required for modelling the response surfaces. An ANN model was developed to predict the responses of lactose crystallinity and free fat content from the processor screw speed, process temperature, milk powder feed rate and lecithin addition rate. Finally, a genetic algorithm was used to search for a combinati on of the process variables for maximum free fat content and maximum crystallinity.
17
Review
Durazzo, A.; Kiefer, J.; Lucarini, M.; Marconi, S.; Lisciani, S.; Camilli, E.; Gambelli, L.; Gabrielli, P.; Aguzzi, A.; Finotti, E.; Marletta, L.
Applications of Spectroscopic Techniques and Chemometrics to milk Fourier-transform infrared (FTIR) spectrometry has been proposed for the determination of milk components, such as fatty acids [53-56], protein fractions [57-59], lactoferrin [60], enzymes [61] and minerals [62-66]. Concerning the quantification of minerals, Soyeurt et al. [62] used IR spectroscopy and prediction models for Ca, K, Mg, Na, and P on a multi-breed data set obtained from sampling over a period of one year. The results of this study showed the capability of quantifying the calcium and phosphorus content in bovine milk directly from the IR spectra. The feasibility of using FTIR to detect heat induced conformational rearrangements of milk proteins, as well as protein-protein and protein-lipid interactions was studied by Grewal et al. [67, 68]. Moreover, they were able to identify changes in the structure and interactions of lipids, proteins, and carbohydrates and proposed them as markers of shelf life [67, 68]. The association of lipids with milk α- and β-caseins was studied by Bourassa et al. [69]. As generally true in the food sector, the recent advancements in instrumentation as well as chemometric pattern recognition techniques have amplified the range of IR spectroscopy applications to dairy products: monitoring contaminants and adulterants [70], classification [71, 72], discrimination, authentication [73], etc. Kamal and Karoui [74] reviewed the applications of the spectroscopic-chemometric approach in the dairy sector. Their review impressively underlines that this approach represents a powerful tool for quality, safety, and authenticity analysis of milk. It is worth mentioning the work of Capuano et al. [72] that consisted of proving fresh grass feeding, pasture grazing and organic farming using FTIR spectroscopy of bovine milk. The authors concluded that organic and conventional milk can be discriminated with acceptable accuracy through FTIR. Concerning applications on safety items, in a review on contaminants of liquid foods, Jha et al. 2016 [75] summarized the potential advantages and limitations of various techniques, including physicochemical methods, chromatography, immunoassays, molecular, electrical, spectroscopy with chemometrics, electronic nose, and biosensors. Their work highlighted how spectroscopy in combination with chemometrics represents a rapid, precise, and sensitive approach for these food products. The recent advances on determination of milk adulterants are also discussed in review articles of Poonia et al. [76] and Nascimento et al. [77]. Spectroscopic technique coupled with chemometrics have been successfully used to detect the adulterants in milk e.g. melamine, hydrogen peroxide, urea, glucose, whey and tetracycline hydrochloride [78-81]. Numerous applications were carried out on melamine in milk and in infant formula [82, 83]. Also, a method for the detection of aflatoxin M1 in milk using spectroscopy and multivariate data analyses was developed [84]. Kümmel et al. [85] used chemometric-assisted FTIR spectroscopy for traking Staphylococcus aureus bacteria from dairy cow to cheese. Furthermore, mid infrared spectroscopy was used for investigating the physiological status of cows [86, 87], their metabolic profile [88], their body energy status and energy intake [89, 90], and their pregnancy status [91]. Another example of a useful application was reported by Chessa et al. [92]: the study of milk coagulation properties by FTIR spectroscopy was proposed as a potential selection criterion for the Italian Holstein. Dagnachew et al. [93] studied the genetic and environmental components of goat milk with FTIR. They found substantial genetic differences/variations and pointed out the possibility of using FTIR spectra as a direct prediction approach and as a monitoring tool in herd management. In this regard, Bonfatti et al. [94] compared the common method of exploiting IR data in animal breeding (estimating the breeding values for the traits predicted by infrared spectroscopy) and an alternative approach. The latter is the direct use of the spectral information (direct prediction) in estimation of breeding values for fine composition and technological properties of milk. The authors concluded that the direct approach is more likely to be effective for traits more related to the main sources of spectral variation (i.e., protein and fat). However, they also concluded that further research is needed to study and understand spectral genetic variations.
18
An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
Review
Another example of the integrated food research approach applied to the milk chain is worth mentioning: Visentin et al. [95] identified factors associated with a range of milk processing characteristics that were predicted by IR spectroscopy analysis. The objectives of this study included the construction of a large database of seasonal calving, grass-based dairy cows, and the development of a model to be used as a support tool that can be employed by the dairy industry to predict and manage their product portfolio influenced by milk process ability. Aside from individual studies, there are several multicenter projects being carried out in the European Network concerning the use of spectroscopy in the food and dairy sector. One aim is the creation of a universal spectroscopic calibration by the standardization of milk samples. All spectra will be merged in a common spectral database in order to create more robust calibrations that can be used throughout the Center Network. This will allow the retroactive application of calibration models for the prediction of milk traits. Eventually, the direct use of the spectral data without restrictions will promote the development of new indicators for dairy farm management, animal health and efficiency [96-98]. A Case Study of Milk-Based Dish: Qualitative Approach Case Study Description and Methods Milk is a basic ingredient of many industrial products and home-made food preparations. An example of a milk-based recipe is a popular sauce frequently used in international and also in Italian dishes: Béchamel sauce. Among other dishes, Béchamel sauce was studied within “QUALIFU” [99], concerning the composition analysis and the investigation of nutritional properties of some Italian dishes commonly consumed and representing traditional Italian cuisine. Samples were experimentally prepared in a dedicated lab-kitchen following a validated and standardized protocol developed within the EuroFIR Network and described in Durazzo et al. [100]. In detail, for every selected recipe, a document collection was carried out from the most popular and traditional cookbooks in Italy (Il cucchiaio d'argento; La cucina italiana, etc). A “standard recipe” was identified and one “preparation protocol” was elaborated in order to just establish ingredients, amounts, preparation and cooking techniques (time, temperature, utensils, etc.). The sampling plan considered the collection of single ingredients in different retail stores and supermarkets. Ingredients were purchased by collecting the main food brands and/or varieties of the same product. Béchamel sauce was made using: 6 brands of whole milk, 6 brands of butter and 2 brands of soft wheat flour (00 type). Each ingredient from all brands was properly weighed and then combined to make a composite sample (pool) before using it for the preparation of the ready-to-eat dish. The dish was assembled and cooked by trained persons according to the “preparation protocol” of the “standard recipe”, by using common household methods and utensils. Identical batches, about 2 kg of each dish, were produced twice in different periods. After cooking, the prepared dishes were weighed once more. Then, they were homogenized, frozen at -30 °C, and then lyophilized for subsequent analyses. Each analysis was carried out in triplicate. In the previous study [100], the focus was on traditional analytical methods to determine proximate composition, mineral content, total polyphenol content and antioxidant properties. In contrast, the present case study aims at applying and evaluating FTIR spectroscopy for food analysis taking Béchamel sauce as an example.
19
Durazzo, A.; Kiefer, J.; Lucarini, M.; Marconi, S.; Lisciani, S.; Camilli, E.; Gambelli, L.; Gabrielli, P.; Aguzzi, A.; Finotti, E.; Marletta, L.
Review
More details about the Béchamel sauce preparation (ingredients, quantity, methods and time of cooking) are reported in Table I. Table I. Ingredients, cooking methods and time of Béchamel sauce Name Béchamel sauce
Ingredients (g/100g)
Cooking
Timing (min)
Milk (83), Butter (8), Flour (8), Salt (0.5)
Melt the butter, add flour, then the milk and cook gently, until mixture thickens
33.50
The FTIR spectra were recorded on a Nicolet iS10 FT-IR spectrometer equipped with a diamond crystal cell for ATR. Spectra were acquired (32 scans/sample or background) in the range of 4000-650 cm-1 at a nominal resolution of 4 cm-1. The spectra were corrected using the background spectrum of air. The analysis was carried out at room temperature. For each measurement, each lyophilized sample was placed onto the surface of the ATR crystal. Before acquiring a spectrum, the ATR crystal was carefully cleaned with wet cellulose tissue and dried using a flow of nitrogen gas. The cleaned crystal was checked spectrally in order to ensure that no residue was retained from the previous sample. The spectrum of every sample was collected 5 times. RESULTS AND DISCUSSION Figure 3a shows the FTIR spectra of two experimental Béchamel sauce preparations. It is possible to discern numerous peaks, which correspond to functional groups and modes of vibration of the indvidual components. The spectra are affected by the time and the type of cooking.
(a)
(b)
Figure 3. (a) Averaged FTIR spectra of two experimental Béchamel sauce dishes in the mid-infrared region (4,000–650 cm−1); (b) PCA of the individual FTIR spectra of the two Béchamel sauce batches.
The spectra in Figure 3a contain a multitude of bands that are more or less characteristic of food -1 samples. The broad band peaking at around 3290 cm corresponds to the OH stretching modes. Water molecules dominate the overall band, but other components containing hydroxyl groups contribute as well. The broad appearance of the band is a result of the complex hydrogen-bonding network. Consequently, the broad band can be deconvolved into sub-bands corresponding to different hydrogen-bonding states. Usually, six individual sub-bands can be observed [101-103]. The lower the wavenumber of an individual sub-band, the stronger the hydrogen-bonding interactions [104]. A detailed analysis of this network, however, is beyond the scope of the present work. 20
An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
Article Review
In the remainder of the spectrum, more specific bands characteristic of Béchamel sauce were highlighted and identified and characteristics bands were assigned as follows. -1
- CH stretching region: asymmetric stretching vibrations of CH3 and CH2 groups are found at 2954 cm and 2917 cm-1, respectively. The corresponding symmetric ones are located at 2871 cm-1 and at 2850 cm-1. These bands are mainly associated with the alkyl chains of the fatty acids [16, 105, 106]. - Spectral region >1500 cm-1: The spectral band at 1741 cm-1 and the shoulder band at 1728 cm-1 are attributed to the absorption of the C=O bonds of the ester groups. They are present in the fat fraction (triglycerides, in which the glycerol is connected with the fatty acids by ester groups) related to the milk and butter ingredients. Further C=O bonds are present in the carbonyl groups of carboxylic acids and proteins [16, 106- 108]. The shoulder at 1728 cm-1, that overlaps the stretching vibration at 1741 cm-1 and leads to a broadening of this peak at the low wavenumber wing, indicates a different molecular oxidation and/or protonation state. For example, the presence of free fatty acids, i.e. COO- is a possible explanation here [108]. The peak at 1236 cm-1 is likely the corresponding C-O stretching mode of the carboxylic acid groups. This is in good agreement with previous work on protonated and de-protonated carboxylic acid groups [109]. The appearance and shape of these bands is probably related to the time and type of cooking and hence may serve as a suitable spectroscopic marker in future work. The region 1700-1500 cm-1 includes two main parts characteristic of proteins with amide groups: an amide I band located around 1700–1600 cm−1 that is related to the stretching of C=O stretching vibrations of peptide bonds (coupled with the deformation of the N–H amide bond I), and an amide II band at 1600–1500 cm−1 that is characteristic of C-N stretching vibrations combined to N–H bending modes [107; 110-112]. Detailed studies on specific signals of the protein secondary structure (i.e.α-helix, ß-sheet, turn structure ßantiparallel, random coil) for the free α- and ß-caseins, and also their interactions with lipids were reported elsewhere [69]. Bassbasi et al. [71] found bands in the spectra of milk that could be assigned to amino acid side chain vibrations due to tyrosine at about 1515 cm-1, phenylalanine at about 1498 cm-1, and proline at about 1454 and 1438 cm-1 As reported by Murphy et al. [113] the peak at absorbance at 1645 cm−1 could be related to Schiff base intermediates formed during the course of Maillard browning. The latter is a reaction of amino acids and glycosides. - Spectral region <1500 cm-1: This spectral is commonly referred to as the fingerprint region. This region is, on the one hand, very rich in information but, on the other hand, difficult to analyze due to its complexity. The fingerprint region includes the amide III spectral region that corresponds to the secondary structure of proteins and is related to N-H bending and C-N stretching vibrations as well as CH2 scissoring of the acyl chains of lipids [114]. Furthermore, it includes the region 1200-900 cm-1, which is associated to polysaccharide peaks related to C−C and C-O stretching modes. In detail, the bands at 1150 cm-1 and 1018 cm-1 are dominated by stretching vibrations of the C–O bond [115]. The peak at 1076 cm-1 is related to the bending of hydroxyl groups (OH) of lactose [16, 116]. Moreover, as reported by Etzon et al. [110], the signatures in the 1060 to 1100 cm−1 range are associated with phosphate groups covalently bound to casein proteins. Maamouri et al. [53] and Karoui et al. [117] used only the region 1500-900 cm-1 as fingerprint region for milk. Because of some interesting signatures, we extend this range for Béchamel sauce. The band at 966 cm-1 is characteristic of out-of-plane bending of –HC=CH− groups of disubstituted olefins in trans conformation [118]. The mode of the corresponding cis conformation is the band at 916 cm-1. The observation of both features in the spectra of Béchamel sauce is presumably due to the presence of trans and cis CLA conjugated fatty acids in butter and other dairy products [119]. The band at 702 cm−1 is likely due to overlapping peaks of the CH2 rocking vibration and the out-of-plane vibration of cis-disubstituted olefins, related to the presence of long chain hydrocarbons [108]. This qualitative approach aiming at the characterization and assignment of the main IR bands of Béchamel sauce represents the basis for the future development of multivariate calibration model. This will be the key for discrimination applications and the investigations of fraud. In this context, the study of Nedeljkovic et al. [120] examined the feasibility of the discrimination of dairy creams and cream-like 21
Review
Durazzo, A.; Kiefer, J.; Lucarini, M.; Marconi, S.; Lisciani, S.; Camilli, E.; Gambelli, L.; Gabrielli, P.; Aguzzi, A.; Finotti, E.; Marletta, L.
analogues (analogues with sunflower oil, coconut oil and palm oil in different milk fat/vegetable fat ratios) using Raman Spectroscopy and chemometric analysis. However, ATR-IR spectroscopy seems to be a more user-friendly and straightforward approach. We have tested the application of PCA to the 10 individual spectra recorded from the two Béchamel sauce batches (5 spectra each). The results of the PCA are plotted in Figure 3b. The averaged spectra in Figure 3a shows only minor differences, which can be attributed to small differences in the preparation of the initial samples and the ingredients. The PCA, however, is capable of utilizing the subtle changes in the spectra and accomplishes a clear distinction between the two batches. Furthermore, this indicates that the homogenization procedure used after preparation of the dishes works well. Therefore, we can conclude that the combination of FTIR and PCA is a powerful method in the field of food research. CONCLUSIONS It is clear how the joined approach of advanced technologies with the multivariate statistical approach enlarges the possibilities to exploit a wide range of food traits and aspects: this direction is leading towards new quality and safety biomarkers. The main perspective is the increased awareness of the importance of sharing data and the creation of an integrated system for calibration and standardization of milk spectra in Multicentre Research Network. The case study of applying FTIR and PCA to Béchamel sauce has shown that combined spectroscopy and chemometrics is a powerful tool for food research and beyond. Manuscript received Oct. 10, 2017; revised version received Jan. 17, 2018; accepted Feb. 5, 2018. REFERENCES
1.
Taiti, C.; Costa, C.; Menesatti, P.; Comparini, D.; Bazihizina, N.; Azzarello, E.; Masi, E.; Mancuso, S. J. Agric. Food Chem., 2015, 95, pp 1757–1763.
2.
Amenta, M.; Fabroni, S.; Costa, C.; Rapisarda, P. Food Chem., 2016, 211, pp 734–740.
3.
Brereton, R. G. Chemometrics for Pattern Recognition. John Wiley and Sons Ltd, Chichester, UK, 2009.
4.
Kumar, N.; Bansal, A.; Sarma, G. S.; Rawal, R. K. Talanta, 2014, 123, pp 186-199.
5.
Otto M. Chemometrics: Statistics and Computer Application in Analytical Chemistry, 3rd Edition. ISBN: 978-3-527-34097-2. Wiley, Weinheim, DE, 2016.
6.
Granato, D.; de Araujo, V. M., Jarvis, B. Food Res. Int., 2014, 55, pp 137-149.
7.
Li-Chan, E. C. Y. Introduction to vibrational spectroscopy in food science. In: Applications of Vibrational Spectroscopy of Food Science. Wiley & Sons: Chichester, UK, 2010, pp 3-30.
8.
Rodriguez-Saona, L. E.; Allendorf, M. E. Ann. Rev. Food Sci. Technol., 2011, 2, pp 467-83.
9.
Casado, B.; Affolter, M.; Kussmann, M. J. Proteomics., 2009, 73, pp 196-208.
10. Deeley, C. M.; Spragg, R. A.; Thelfall, T. L. Appl. Spectrosc., 1991, 47A, pp 1217–1223. 11. Chieng, N.; Rades, T.; Aaltonen, J. J Pharm Biomed Anal., 2011, 55, pp 618–644. 12. Matero, S.; Den Berg, F. V.; Poutiainen, S.; Rantanen, J.; Pajander, J. J Pharm Sci., 2013, 102, pp 1385–1403.
13. Haaland, D. M.; Thomas, E. V. Anal. Chem., 1988, 60, pp 1193–1202. 14. Wold, S.; Sjostrom, M. Chemom Intell Lab Syst., 2001, 58, pp 109–130. 15. Jolliffe, I. T. J. R Stat. Soc., 1982, 31, pp 300–303. 16. Iñón, F. A.; Garrigues, S.; de la Guardia, M. Anal. Chim. Acta, 2004, 513, pp 401–412. 22
An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
Article Review
23
Review
24
Durazzo, A.; Kiefer, J.; Lucarini, M.; Marconi, S.; Lisciani, S.; Camilli, E.; Gambelli, L.; Gabrielli, P.; Aguzzi, A.; Finotti, E.; Marletta, L.
An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
Review
Bassbasi
25
Review
26
Durazzo, A.; Kiefer, J.; Lucarini, M.; Marconi, S.; Lisciani, S.; Camilli, E.; Gambelli, L.; Gabrielli, P.; Aguzzi, A.; Finotti, E.; Marletta, L.
An Innovative and Integrated Food Research Approach: spectroscopy applications to milk and a case study of a milk-based dish
Review
27
Br. J. Anal. Chem., 2018, 5 (18), 28-39 DOI: 10.30744/brjac.2179-3425.2018.5.18.28-39
Article
Download
Development of an Analytical Methodology for Chemical Profile of Cocaine seized in Rio de Janeiro, Brazil Wagner Felippe Pacheco1*, Vanessa Gomes Kelly Almeida2, Ricardo J. Cassella1, Fábio Grandis Lepri1 1 Instituto de Química, Universidade Federal Fluminense, Outeiro São João Batista s/n, Centro, Niterói, RJ, Brazil. ZIP 24020-141 2 Departamento de Química, Universidade Federal Rural do Rio de Janeiro, Rodovia BR 465, Km 07 - Zona Rural, Seropédica, RJ, Brazil. ZIP 23890-000 Graphical Abstract
A hierarchical cluster analysis, which could be used to obtain important information regarding the origin and distribution network of cocaine, was created from data on cocaine content and concentrations of main contaminants and adulterants.
This work presents the development of analytical methodologies to determine cocaine, its major adulterants (acetaminophen, diltiazem, caffeine, lidocaine and phenacetin), lead and manganese in 17 samples of cocaine-derived drugs seized by the Civil Police of the state of Rio de Janeiro, Brazil, during the year 2013. Cocaine and major adulterants were determined by high-performance liquid chromatography with diode array detection (HPLC-DAD), whereas the inorganic contaminants were determined by graphite furnace atomic absorption spectrometry (GFAAS). Approximately 80% of the analyzed samples contained at least one adulterant above the limit of quantification, whereas metals (Pb and/or Mn) did in almost all the samples. The data obtained from the small set of analyzed samples allowed the application of a hierarchical cluster analysis (HCA), which indicated that the samples could be classified according to their chemical composition. Keywords: Cocaine, characterization, hierarchical cluster analysis, adulterants. INTRODUCTION One of the most critical problems that affects modern society is the illicit consumption of drugs, such as marijuana, cocaine and others. Nowadays, this problem is a major public, social, economic and legal concern. The consumption of drugs moves billions of dollars per year, consisting of an illicit market not only in Brazil, but also in many other countries. According to the World Drug Report of 2015 [1], it is estimated that approximately 246 million people, about 5.0 % of the adult world population, had used an 28
*wfpacheco@id.uff.br https://orcid.org/0000-0002-1835-9420
Development of an analytical methodology for chemical profile of cocaine seized in Rio de Janeiro, Brazil
Article
illicit drug at least once in the year 2010. The document also reports that the consumption of cocaine remained stable among the population aged between 15 and 64 years (approximately 19 million users) and that there was an increase in consumption of drugs in Brazil. Brazil is not considered one of the biggest producers of cocaine, but due to its strategic location in South America and vast border area, figures as an important route for the distribution of the drug. Cocaine is produced mainly in Colombia, Peru and Bolivia and is sent to Europa and Africa through Brazilian ports and airports. Besides serving as a route for drug trafficking, Brazil is a large consumer market. A direct consequence of the high consumption is the illegal cocaine trafficking, which generates high rates of urban violence (territorial disputes between rival groups and clashes with security forces, among other types of crime), a daily problem that occurs especially in the metropolitan region of Rio de Janeiro city, in Brazil [2]. Several actions have been taken by the Brazilian government to suppress drug trafficking and reduce the violence caused by such trafficking. However, these actions have not yet reached the desired effect. Among the most effective actions observed in other countries, actions involving intelligence and forensics have proven to be the most effective in combating crime and trafficking. Within this scope, drug profiling can be highlighted as a powerful tool in combating drug trafficking [3-7]. Whether of natural origin (such as heroin, cocaine or marijuana) or synthetic (such as amphetamine), illicit drugs are such a complex mixture that they are rarely found as chemical-pharmaceutical products in their pure form. The clandestine process of production of drugs generates a chemical signature in the final product from of all the supplies and materials used in the production. These materials are present as impurities, and in the case of trace elements, they are unintentionally introduced in the production process, or as excipients purposely added during the production of the drug [4]. From the standpoint of chemical composition, the substances present in illicit cocaine may be classified into three main groups: (1) natural components that are co-extracted from the raw material of the drug (as alkaloids present in the coca plant); (2) parallel products generated during the various stages of synthesis/ extraction/dilution of the drug; (3) other products deliberately added to the final composition of the drug in order to dilute the active ingredient and increase the profits of drug dealers, giving rise to a broad range of concentration of cocaine in the final product, a parameter which can be easily monitored and used to characterize the drug [5]. The chemical analysis of seized cocaine can provide important information for the guidance of security forces. From an investigative perspective, the chemical profiling of drugs can allow to three main actions: (1) establish correlation among samples; (2) classify the seized drug into different classes of samples to facilitate processing and quantification of networks and drug delivery and; (3) identify the source of drug – a clandestine laboratory or a geographical region where the raw material was obtained [5]. Papers have been published about the development and/or application of analytical methods for obtaining the chemical profile of drugs seized in different regions. Most of them are based on gas chromatography-mass spectrometry (GC-MS) [4-7] as recommended in the manuals of the United Nations Office on Drugs and Crime (UNODC) [1]. High-performance liquid chromatography (HPLC) associated with mass spectrometry (HPLC-MS) has also been employed. However, this is a more costly and technically complex technique, which requires skilled labor for conducting the analysis. The use of cheaper and more widespread detectors, such as UV detectors, are advisable because they provide sufficient sensitivity, are easy to operate and are readily available in analytical laboratories. HPLC-UV there are not no difficulties related to the volatility and thermal stability of the analytes, leading an excellent separation of compounds. Moreover, the use of the HPLC-UV technique saves time and requires no complex steps of sample preparation [6]. Although there are many studies about the quantification of contaminants of cocaine seized in different countries [7-19], less works on the quantification of cocaine, adulterants and contaminants in samples seized in Brazil have been published. Goulart Jr. [20] determined the cocaine content and the main adulterants in samples of cocaine supplied by the Brazilian Federal Police, which were seized in different regions of Brazil in 2009 to 2011. The samples were analyzed using gas chromatography with a flame 29
Pacheco, W. F.; Almeida, V. G. K.; Cassella, R. J.; Lepri, F. G.
Article ionization detector (GC-FID) and the concentrations of cocaine found ranged from 1.43% up to 97.08%, with an average concentration of 65% in terms of mass. The contaminants found in the samples were phenacetin, lidocaine, caffeine, diltiazem, hydroxyzine, benzocaine and levamisole. Floriani et al. [3] developed a methodology for the simultaneous determination of cocaine and main contaminants (caffeine, lidocaine, phenacetin, benzocaine and diltiazem) in samples provided by the Institute of Criminology of Paraná (Brazil), using high performance liquid chromatography system with a diode array detector (HPLC-DAD). The samples were seized between 2007 and 2012 and approximately 71% of them had noticeable concentrations of caffeine, lidocaine, phenacetin, benzocaine and diltiazem. Bernardo et al. [21] analyzed drug samples seized in Minas Gerais state, Brazil, during the year 2001. Approximately 90% of the samples contained cocaine, 50.2% of the samples presented caffeine, 65% presented lidocaine and 11% presented prilocaine. The identification of cocaine and adulterants was carried out by thin layer chromatography, whereas quantification was by GC-FID. Carvalho and Mídio [22] reported the presence of lidocaine, procaine and caffeine as the main adulterants in samples of cocaine seized in the city of São Paulo (Brazil) in 1997. The samples had a cocaine content ranging from 20 to 70%. Oliveira [23] employed HPLC-UV to determine the content of cocaine in samples seized by the police. The results indicated the presence of cocaine in all samples, with levels ranging from 37.4% to 95.6% in terms of mass. Magalhães et al. [24] developed a CG-MS method to quantify cocaine, caffeine, lidocaine and benzocaine in street cocaine samples seized in two different states of Brazil (Minas Gerais and Amazonas) in July 2008 to May 2010. They found different concentrations of cocaine and adulterants in the samples from each region. De Souza et al. [25] also used CG-MS to quantify cocaine, caffeine and lidocaine in cocaine seized in the state of Espírito Santo, Brazil, in samples collected in the years 2008 to 2012. Lapachinske et al. [26] employed gas chromatography with nitrogen-phosphorus detector (GC–NPD) for the quantification of cocaine, caffeine, 4-dimethylaminoantipyrine, levamisole, lidocaine and phenacetin in illicit samples. The method was successfully applied to drug samples seized by the Brazilian Federal Police in the International Airport of Sao Paulo and mailing services during the year 2011. More recently, the determination of cocaine on banknotes in circulation in the metropolitan area of Rio de Janeiro has been published. It was observed that more than 80% of the banknotes presented detectable amounts of cocaine. However, typical cocaine adulterants in the banknotes were not investigated [31]. Although it is less common than the organic content analyses, there are some works in literature dealing with the inorganic composition of seized drugs. In this case the detection is usually based on atomic emission or absorption spectrometry, or mass spectrometry [28-30]. The main objective of the present work was to develop analytical methodologies for the determination of cocaine and the major adulterants (acetaminophen, diltiazem, caffeine, lidocaine and phenacetin) by HPLC-DAD, and some inorganic contaminants (lead and manganese) by graphite furnace atomic absorption spectrometry (GFAAS) in samples of cocaine seized by the police in Rio de Janeiro, Brazil, in 2013. The concentrations of these substances were employed to classify the samples in different groups according to their chemical composition. To do so, a hierarchical cluster analysis (HCA) was applied, providing a tool that can be used by public security forces to investigate possible drug sources. MATERIALS AND METHODS Apparatus and instruments The determination of the major adulterants was carried out with an Ultimate 3000 (Dionex, Sunnyvale, CA, USA) high-performance liquid chromatography system equipped with a diode-array detector. A Zorbax 300SB-C18 (Agilent, Santa Clara, CA, USA) analytical column (150 × 2.1 mm, 5 µm particle size) was employed for the separation of the analytes. The determination of Pb and Mn was carried out by GF AAS using a Varian (Mulgrave, Australia) graphite furnace atomic absorption spectrometer, model AA240Z, equipped with a Varian GTA 120 longitudinally heated atomizer unit and a Varian PSD 120 auto sampler. Graphite tubes with integrated 30
Development of an analytical methodology for chemical profile of cocaine seized in Rio de Janeiro, Brazil
Article
platform (Varian part no. 63-100026-00) were used and all measurements were in integrated absorbance mode. Background correction was performed with a polarized Zeeman-effect with a transverse magnetic field, operated at a constant magnetic field strength of 0.8 T. Lead and Mn were measured at 283.3 nm and 279.5 nm, respectively, whereas the spectral bandwidth was 0.2 nm. Individual hollow cathode lamps of Pb and Mn, operated at 7.0 mA and 5.0 mA, respectively, were employed as radiation sources. To filter the solutions before injecting into the chromatographic system, a NylonTM membrane (47 mm, 0.45 µm pore diameter) from Unifil (São Paulo, Brazil) was used. Standards and samples were weighed using an analytical scale from Shimadzu, model AUY220 (Tokyo, Japan), and the pH measurements were performed with a DM-22 pH meter from Digimed (São Paulo, Brazil). Solutions were homogenized with a vortex shaker, model 52K, from CAEL (Rio de Janeiro, Brazil). The removal of air bubbles from the solutions was performed with the aid of an ultrasonic bath (frequency of 40 KHz) supplied by Unique (São Paulo, Brazil), model Ultracleaner 1600. The solid-phase extraction was conducted using Phenomenex (USA) Strata™-X 33 µm polymeric reversed phase cartridges, containing 60 mg mL-1 of solid phase. The hierarchical cluster analysis was performed with Statistica software version 3.0. Reagents and solutions The deionized water employed in this work was purified in a Millipore Direct-Q 3 (Milford, USA) system to achieve a resistivity of at least 18.2 MΩ cm. Acetonitrile, methanol, ethanol and acetone were all HPLC grade and were supplied by Tedia (Fairfield, OH, USA). Glacial acetic acid used in the preparation of the buffer solution was supplied by Vetec (Rio de Janeiro, Brazil). A 1000 mg L-1 standard solution of cocaine was purchased from Cerillant (Round Rock, TX, USA) in ampoules containing 1 mL of acetonitrile. The diluted standard solutions of cocaine were prepared in 10 mL volumetric flasks, by suitable dilution of the 1000 mg L-1 stock solution with acetonitrile. Solid standards of caffeine, diltiazem, acetaminophen, phenacetin and lidocaine were purchased from -1 Sigma-Aldrich. Stock solutions 200 mg L of these substances were prepared, separately, in 100 mL flasks by dissolving 20 mg of each standard in 0.01% v/v acetate buffer solution with pH 3.9. Diluted solutions of caffeine, diltiazem, acetaminophen, phenacetin and lidocaine solutions were prepared in 10 mL volumetric flasks by appropriate dilution of the 200 mg L-1 stock solution with 0.01% v/v acetate buffer solution of with 3.9. Stock standard solutions containing 1000 mg L-1 of Mn or Pb and also HNO3 65% m/m were purchased from Tedia (São Paulo, Brazil). Calibration solutions were prepared by appropriate dilution of the 1000 mg L-1 stock solutions of each metal in 1% v/v HNO3 solution in 10 mL volumetric flasks. Palladium modifier solution 10.000 mg L-1 was purchased from Merck (Darmstadt, Germany). Preparation of samples for the determination of cocaine and adulterants by HPLC-DAD All samples analysed in this work were provided by the Institute of Criminology Carlos Eboli (ICCE) of the Civil Police of the State of Rio de Janeiro, Brazil. The extraction of cocaine and adulterants (diltiazem, acetaminophen, phenacetin and the lidocaine) from the samples was carried out by mixing 50 mg of each sample with 25 mL of a 1.7 mmol L-1 acetate buffer solution (pH = 3.9), in a 50 mL capped polyethylene tube. The mixture was agitated for 10 min with the aid of a vortex mixer and the obtained solution was percolated (5.0 mL) through a Strata-X (polymeric reversed phase) cartridge in order to retain the target compounds and eliminate possible interferents. This procedure provided a convenient clean-up of the sample solution before its injection into the chromatographic system. The cartridges were previously conditioned with 5 mL of a 1.7 mmol L-1 acetate buffer solution (pH = 3.9), and the elution was conducted with 2 mL of acetonitrile. The obtained extract was properly diluted for 5.0 mL with 1.7 mmol L-1 acetate buffer solution (pH = 3.9) prior to its injection into the chromatographic system.
31
Pacheco, W. F.; Almeida, V. G. K.; Cassella, R. J.; Lepri, F. G.
Article Chromatographic determination of cocaine and adulterants The quantification of cocaine and adulterants was carried out by injecting 20 µL of the treated extract (sample or standard) into the chromatographic system, using a mixture of acetonitrile and acetic acid -1 -1 solution (1.7 mmol L ) as mobile phase. The mobile phase was pumped at a flow rate of 1.0 mL min and the elution was performed in gradient mode. The temperature of the column was set at 25 ºC. The gradient of the mobile phase started with 10% acetonitrile, which increased to 50% over 20 min. After finishing the chromatographic run, the proportion of acetonitrile returned to the initial condition (10%) in order to allow the injection of a new extract aliquot. Sample preparation for Mn and Pb determination by GFAAS The sample preparation for Mn and Pb quantification consist of dissolving 25 mg of sample in 5 mL of a 30% v/v HNO3 solution; aliquots of the obtained solution were diluted with deionized water before their introduction into the graphite tube. In general, the samples solutions were diluted 1:100 and 1:20 for the measurement of Mn and Pb, respectively. The analytes were determined by introducing 20 µL of the solution (sample or calibration solution) into the platform of the graphite tube and running the temperature program given in Table I, which was optimized in the present work. In the case of Pb, 10 µL of a 1000 mg L-1 Pd(NO3)2 solution as chemical modifier was co-injected with calibration or sample solutions. Table I. Heating program employed for the measurement of Mn and Pb by GFAAS. Step Drying Pyrolysis Atomization Cleaning
Temperature o ( C) 50 120 1200 (Mn) 1000 (Pb) 1800 (Mn) 2200 (Pb) 2000 (Mn) 2300 (Pb)
Ramp (s) 5 40
Hold (s) 0 10
Ar flow rate -1 (mL min ) 300 300
1
6
300
1
3
0
2
0
300
Evaluation of the solubility of the samples Among the 17 samples analyzed in this work eight of them were used in the solubility test. Samples with different forms of distribution were selected. The solubility test was performed by mixing 50 mg of each sample with 10 mL of six different solvents/ -1 solutions (methanol, acetonitrile, water, 0.01% v/v acetate buffer solution with pH = 3.9, 6 mol L HCl and 7 mol L-1 HNO3) in a 15 mL capped polyethylene tube. The obtained mixtures were agitated with the aid of a vortex mixer in order to achieve maximum solubilization of the samples. All samples were highly soluble in only HCl and acetate buffer solutions. Therefore, acetate buffer solution was chosen as one of the solvents for the mobile phase used in the chromatographic system. RESULTS AND DISCUSSION Development of the HPLC-DAD method for cocaine and adulterants determination The development of the chromatographic method for the determination of cocaine and adulterants (caffeine, diltiazem, lidocaine, acetaminophen and phenacetin) was carried out using a test solution -1 -1 containing 5.0 mg L of each analyte, prepared in 1.7 mmol L acetic acid solution at pH 3.9. The initial chromatographic conditions were those cited on the certificate of the cocaine standard, where the use of -1 a mobile phase composed of 20:80 acetonitrile/water, pumped at 1.0 mL min in isocratic mode is recommended. The temperature of the column was 30 ºC and the injection volume 20 µL. In this condition, a convenient resolution was not achieved, strong overlapping of the peaks was observed. However, suitable resolution of the chromatographic peaks was achieved using a mobile phase containing acetonitrile and acetic acid solution (1.7 mmol L-1, pH = 3.9) in gradient mode. (For details, see the experimental section). 32
Development of an analytical methodology for chemical proďŹ le of cocaine seized in Rio de Janeiro, Brazil
Article
Once chromatographic conditions that allowed suitable separation of the substances of interest were established, the method was evaluated to identify possible interferent substances in the samples. Direct analysis of the sample solutions obtained by dissolution of the samples was not possible, because the presence of other compounds gave rise to a chromatogram with a large number of overlapped peaks. Some unknown substances co-eluted with the analytes, making impossible the quantiďŹ cation of the cocaine and the adulterants in the sample solutions. In order to solve this drawback, a solid phase extraction (SPE) procedure was evaluated for clean-up of the extracts before their injection into the chromatographic system. For such evaluation, test solutions of cocaine and adulterants were analysed. The SPE procedure was ďŹ rstly tested for cocaine recovery of, the major substance present in the sample extracts. The results obtained in the recovery of cocaine are given in Table II. Table II. Recovery test for cocaine using different solvents and solid-phase extraction
Mass of cocaine (mg)
Solvent
Added
Recovered
Acetonitrile
100.0
97.74
Methanol
100.0
89.2
100.0
77.4
1.0 x 10 mol L of HCl
100.0
57.4
1.0 x 10-3 mol L-1 of NaOH
100.0
33.6
Water -3
-1
n=3
As can be seen in Table II, quantitative recovery of cocaine was obtained when the extracts were cleaned-up by SPE and using acetonitrile (97.4%) as eluent, evidencing that no losses of the analyte occurred during the clean-up procedure. Therefore, acetonitrile was chosen as eluent of cocaine. Afterwards, the same SPE procedure was evaluated for the recovery of the cocaine adulterants. Recovery ranging from 95.2 to 102% was observed using the same solid phase (Strata-X polymeric reversed cartridge) and the same eluent (acetonitrile), indicating that the proposed SPE procedure could be applied to clean-up the extracts. Figure 1 shows the chromatogram obtained for a sample extract enriched with cocaine and adulterants, which was treated using the SPE procedure. In Figure 1 it is possible to observe that a satisfactory resolution was achieved for all substances, which demonstrated the effectiveness of the SPE clean up. Therefore, this procedure could be applied in the analysis of the extracts obtained from the analyzed samples.
Figure 1. Typical chromatogram of a cocaine sample extract enriched with (5.0 mg L-1 of). 1: acetaminophen; 2: caffeine; 3: lidocaine; 4: phenacetin; 5: cocaine; 6: diltizazem. Wavelenght detection at 230 nm; mobile phase: (A) acetonitrile (B) 1.7 mmol L-1 acetic acid solution, varying from 10% to 50% A in 20 minutes. 33
Pacheco, W. F.; Almeida, V. G. K.; Cassella, R. J.; Lepri, F. G.
Article Analytical characteristics of the HPLC method for the determination of cocaine and adulterants The analytical figures of merit (see Table III) of the method were obtained for all analytes (cocaine and adulterants) at the experimental conditions (sample preparation and measurement) evaluated and selected. The limits of detection (LOD) and quantification (LOQ) of the method were calculated, following the 3 (for LOD) and 10 (for LOQ) [34] using the standard deviation of the lower value of the analytical curve (2.00 mg L-1). Table III. Figures of merit of the method for cocaine and adulterants determination by HPLC-DAD. Analyte
Wave length (nm)
Working range -1 (mg L )
Cocaine
230
2.00 - 100
Caffeine
274
2.00 - 200
Diltiazem
230
2.00 - 100
Acetaminophen
248
2.00 - 100
Fenacetin
248
2.00 - 200
Lidocaine
230
5.00 - 200
Typical linear regression equation of the analytical curve y = 0.9455 x + 0.1023 y = 0.9595 x + 2.967 y = 1.581 x + 2.244 y = 1.125 x + 7.712 y = 1.013 x + 1.618 y = 0.380 x 0.848
r
LOD -1 (µg g )
LOQ -1 (µg g )
Precision (as RSD %)
1.000
0.2
0.7
2.1
0.998
0.3
1
3.2
0.998
0.2
0.7
3.5
0.996
0.3
1
2.1
0.999
0.2
0.7
4.1
0.999
0.7
2
4.1
2
The precision was estimated as the relative standard deviation (RSD) of six independent analyses of the sample C-10. In this experiment, the sample aliquots were submitted to the whole treatment (dissolution and solid-phase extraction) as described in the experimental section. As can be seen in Table III, the RSD was always lower than 5%. The accuracy of the method was checked by analyte recovery test, since no certified materials of this kind of sample are commercially available. The analyte recovery test was conducted by spiking the solution obtained from sample C-10. In this case, the sample solution was analyzed with (5.0, 50.0 or 100.0 mg L -1) and without analyte spiking. As can be seen in Table IV, excluding two points, the recovery in the range of 94.9 and 110.8 % was achieved. A recovery in the range of 80-120 is considered ideal for analysis of seized drug [35]. The results of 156.9 for caffeine and 123% for lidocaine could be considered as outlines. Table IV. Results obtained in the recovery test of cocaine, caffeine, diltiazem, acetaminophen, phenacetin and lidocaine spiked to solutions of cocaine sample. Concentration found after each addition and recovery (%) -1
C0 Analyte
Addition of 5.00 mg L -1
-1
mg L
mg L
Recovery
Cocaine
5.80
10.91
Caffeine
48.00
53.53
Diltiazem
7.60
Acetaminophen
17.23
Phenacetin Lidocaine
-1
Addition of 50.00 mg L -1
-1
Addition of 100.00 mg L -1
mg L
Recovery
mg L
Recovery
101
59.14
106
100
105.8
101
106.82
109
106
156.9
12.18
96.7
58.75
102
99.1
106.6
22.45
101
63.80
94,9
94.5
110.8
5.32
10.21
98.9
53.22
96,2
100
105.3
15.07
21.68
108
64.16
98,6
107
123.1
Development of the GF AAS method for Mn and Pb determination A brief study was carried out to set suitable experimental conditions for Mn and Pb determination. Firstly, the graphite furnace temperature program was investigated, using the solution obtained by dissolving 50 mg of samples C-10 in 5 mL of 7 mol L-1 HNO3, with subsequent filtration of the solution through a PVDF membrane filter - 13 mm diameter 0.45 µm pore seize sigma. The filtration was needed due a small quantity of insoluble material after the acidic treatment. 34
Development of an analytical methodology for chemical profile of cocaine seized in Rio de Janeiro, Brazil
Article
The drying step of the temperature program was maintained as recommended by the manufacturer, since an aqueous solution was introduced into the graphite tube. The general temperature program employed in this work was previously shown in Table I. The construction of the pyrolysis and atomization temperature curves followed a well know procedure. Firstly, the pyrolysis temperature was varied while the atomization temperature was kept constant. In the case of Mn, the pyrolysis temperature was varied from 200 to 1800 ºC, keeping the atomization temperature of 2000 ºC. For Pb, the pyrolysis temperature was varied a 200 to 1600 ºC, for an atomization temperature at 2200 ºC. In order to verify possible interferences of the sample matrix, the pyrolysis and atomization temperature curves were also constructed by analyzing solutions of Pb and Mn. The profiles of the pyrolysis and atomization temperature curves are shown in Figure 2. As can be seen in this figure, very similar profiles were obtained for Mn and Pb solutions. This behavior was an initial indication that the sample matrix did not interfere in the Pb and Mn determination by GFAAS. As a consequence, the pyrolysis and atomization temperatures for Mn were set at 1400 ºC and 1800 ºC, respectively, whereas for Pb they were 1200 ºC and 2200 ºC, respectively.
Figure 2. Pyrolysis and atomization temperature curves for (A) Pb and (B) Mn solution test and sample extract.
In order to confirm that the sample matrix did not interfere in the determination of Mn and Pb by GFAAS, analytical curves prepared from calibration solutions were compared with analyte addition analytical curves. As expected, statistically significant differences were not observed for the slopes of the analytical curves. For Mn, the slope of the analytical curve was 0.054 ± 0.006 L μg-1 (r2 = 0.992) and the slope of the analyte -1 2 addition curve was 0.058 ± 0.004 μg (r = 0.999). In the case of Pb, the slopes of the analytical and analyte addition curves were 0.0025 ± 0.003 (r2 = 0.998) and 0.0026 ± 0.004 (r2 = 0.993), respectively. In the following step, the LODs and LOQs of the method were calculated, following the 3 (for LOD) and 10 (for LOQ) [34]. The LOD and LOQ were 8 ng g-1 and 28 ng g-1 for Mn, and 20 ng g-1 and 65 ng g-1 for Pb, respectively. Sample analysis The developed methods were then applied to the determination of cocaine, caffeine, diltiazem, acetaminophen, phenacetin, lidocaine, Mn and Pb in the samples of seized drugs. The results obtained in the analysis of all 17 samples are presented in Table V. These results are reported already in the concentration found in the drug (mg/g or µg/g) and not in the aqueous phase. This conversion was made according the extraction steps describe in the preparation of samples procedure.
35
Pacheco, W. F.; Almeida, V. G. K.; Cassella, R. J.; Lepri, F. G.
Article Table V. Results of the analyses of cocaine samples seized in the city of Rio de Janeiro, Brazil. Caffeine (mg/g)
Diltiazem (mg/g)
Acetaminophen (mg/g)
Phenacetin (mg/g)
Lidocaine (mg/g)
Cocaine (%)
Mn (μg/g)
Pb (μg/g)
(C_1)
3.40
0.054
1.5
0.11
1.20
11.4
3.33
0.473
(C_2)
0.038
0.042
3.4
0.10
0.92
13.5
1.37
1.60
(C_3)
3.50
< ? LOQ
2.8
0.18
1.50
16.7
1.39
0.310
(C_4)
0.21
< ? LOQ
2.1
0.45
0.74
14.7
1.17
1.48
(C_5)
0.18
< ? LOQ
9.6
0.51
< LOQ
16.2
0.53
1.19
(C_6)
< ? LOQ
0.033
< ? LOQ
<? LOQ
0.56
9.20
3.97
1.67
(C_7)
4.2
< ? LOQ
< ? LOQ
<? LOQ
1.90
9.10
1.55
2.45
(C_8)
0.26
< ? LOQ
3.1
0.41
< LOQ
11.2
5.56
0.213
(C_9)
< ? LOQ
< ? LOQ
3
0.30
< LOQ
7.20
1.12
0.193
(C_10)
1.7
0.05
< ? LOQ
<? LOQ
1.20
9.40
7.43
? LOQ <
(C_11)
0.17
< ? LOQ
< ? LOQ
<? LOQ
1.70
4.60
1.91
0.987
(C_12)
2.1
< ? LOQ
3
<? LOQ
0.48
12.6
3.83
0.108
(C_13)
1.9
< ? LOQ
2.7
<? LOQ
0.45
26.9
5.27
0.316
(C_14)
? LOQ <
? LOQ <
? LOQ <
<? LOQ
? LOQ <
28.4
1.84
0.140
(C_15)
< ? LOQ
< ? LOQ
< ? LOQ
<? LOQ
< ? LOQ
14.2
1.54
0.128
(C_16)
< ? LOQ
< ? LOQ
< ? LOQ
<? LOQ
< ? LOQ
27
1.52
0.116
(C_17)
? LOQ <
? LOQ <
? LOQ <
<? LOQ
? LOQ <
11.4
? LOQ <
? LOQ <
Relatively low concentration of cocaine was found in all samples, indicating that drug dealers have diluted the drug to increase the profit generated by trafficking. This hypothetical procedure has been pointed out in other studies; in the case of Brazil, it was observed that the further from the Brazilian borders the drugs were seized, the greater the dilution factor [11]. The results of the analysis revealed that approximately 80% of the samples had organic adulterants. Whereas caffeine was the most common found, present in 69% of the samples. Manganese and Pb were investigated because they are present in the reagents used in the process of extraction and refining of cocaine. A strong acid is needed to extract cocaine from the coca plant and, according to police reports [32-33], the H2SO4 solution used in car batteries, which contains high levels of Pb, is largely employed for that purpose due to the low price of the H2SO4 solution. Also according to police reports, potassium permanganate solution is used to clarify the cocaine, which is then contaminated with Mn. Of the samples analyzed in this study, 94% of them contained Mn, whose concentrations ranged -1 from 0.53–7.43 mg g . Lead was found in 88% of samples, in concentrations ranging from 0.108–2.45 mg -1 g . This result agrees with other works found in literature dealing with inorganic composition of seized drugs [25,29-30], thus suggesting that the contamination by metal is due reagents used in the extractions steps of the drug. Drug Profile The methods developed in this work gave access to information that could be used to create a chemical signature of the drug (drug profile), which may be useful to differentiate seized drugs. The presence of some components, at certain concentrations, may indicate the way that a given drug has been processed. In this context, the similarity of the chemical profiles of the samples can indicate whether they have a different origin. This information can be obtained by multivariate analysis of the data. To obtain this information, it is still necessary to use an appropriate mathematical tool. In the present case, Hierarquical Cluster Analysis (HCA). For HCA, the data (concentration of each substance) was normalized to eliminate the effect of the magnitude of the concentrations on the comparation of the standard deviation, which indicates the similarity of the samples. The results of the HCA are given in the dendogram in Figure 3. According to Figure 3, the samples can be classified into three distinct groups. The first group was composed of the samples C_4, C_5, C_8 and C_9; the second, by samples C_3, C_12, C_13, C_14, C_ 15 and C_16; and the third , by samples C_1, C_2, C_6, C_7, C_10 and C_11. 36
Development of an analytical methodology for chemical profile of cocaine seized in Rio de Janeiro, Brazil
Article
This classification was consistent with the physical appearance of the samples and with the information provided by the Police; the samples of the second group showed very similar texture and color and were distinct from the samples classified in groups 1 and 3. Also according to Police information, all samples of the third group were seized from the same dealers.
Figure 3. Dendrogram obtained from HCA for the samples of cocaine seized in the city of Rio de Janeiro, Brazil.
CONCLUSIONS The developed HPLC-DAD method was suitable for simultaneous quantification of cocaine, caffeine, diltiazem, acetaminophen, phenacetin and lidocaine in seized drug samples. Determination of Mn and Pb in the samples was possible by GFAAS, after just dissolving the sample with nitric acid solution. All samples analyzed contained low concentrations of cocaine (less than 30%), indicating that they were diluted before being marketed. In general, the samples (contained at least one adulterant) and caffeine was the most abundant, being found in 69% of the samples. Almost all samples presented detectable concentrations of manganese and lead. Multivariate analysis of concentration of contaminants and adulterants can yield a signature of the ilicit drugs, allowing important information regarding their origin and distribution network. An analysis of a larger number of samples (only 17 samples were available in the present study) would enable better classification, and could provide more information about the seized drugs, assisting the intelligence service of the public security forces. ACKNOWLEDGEMENTS The authors would like to thanks the Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro, Brazil (FAPERJ) for the sponsoring of this work. Manuscript received Oct. 3, 2017; 1th round revised manuscript received Dec. 5, 2017; 2nd round revised manuscript received Feb. 21, 2018; manuscript accepted March 20, 2018.
37
Pacheco, W. F.; Almeida, V. G. K.; Cassella, R. J.; Lepri, F. G.
Article REFERENCES
1. United Nations Office on Drugs and Crime (UNODC). World Drug Report 2015, 2015. DOI: 10.1017/CBO9781107415324.004. 2. Dowdney, L. Um Estudo de Caso de Crianças em Violência Armada Organizada no Rio de Janeiro. 7Letras, Rio de Janeiro, 2004. 3. Floriani, G.; Gasparetto, J. C.; Pontarolo, R.; Gonçalves, A. G. Forensic Sci. Int. 2014, 235, pp 32-38. DOI: 10.1016/j.forsciint.2013.11.013. 4. Lociciro, S.; Hayoz, P.; Esseiva, P.; Dujourdy, L.; Besacier, F.; Margot, P. Forensic Sci. Int. 2007, 167, pp 220-228. DOI: 10.1016/j.forsciint.2006.06.052. 5. Dujourdy, L.; Besacier, F. Forensic Sci. Int. 2008, 179, pp 111-122. DOI: 10.1016/j.forsciint.2008.04.024. 6. United Nations Office on Drugs and Crime (UNODC), 'Analysis' 2004. DOI: 10.1007/s12117-9971166-0 7. Morelato, M.; Beavis, A.; Tahtouh, M.; Ribaux, O.; Kirkbride, P.; Roux, C. Forensic Sci. Int. 2013, 226, pp 1-9. DOI: 10.1016/j.forsciint.2013.01.003. 8. Morelato, M.; Beavis, A.; Tahtouh, M.; Ribaux, O.; Kirkbride, P.; Roux, C. Sci. Justice 2014, 54, pp 32-41. DOI: 10.1016/j.scijus.2013.08.006. 9. de Araujo, W. R.; Maldaner, A. O.; Costa, J. L.; Paixão, T. R. L. C.. Microchem. J. 2015, 121, pp 213218. DOI: 10.1016/j.microc.2015.03.012. 10. Kuwayama, K.; Tsujikawa, K.; Miyaguchi, H.; Kanamori, T.; Iwata, Y.; Inoue, H.; Saitoh, S.; Kishi, T. Forensic Sci. Int. 2006, 160, pp 44-52. DOI: 10.1016/j.forsciint.2005.08.013. 11. Perkal, M.; Ng, Y. L.; Pearson, J. R. Forensic Sci. Int. 1994, 69, pp 77-87. DOI: 10.1016/03790738(94)90051-5. 12. Aehle, E.; Dräger, B. J. Chromatogr. B Anal. Technol. Biomed. Life Sci. 2010, 878, pp 1391-1406. DOI: 10.1016/j.jchromb.2010.03.007. 13. Fucci, N.; De Giovanni, N. Forensic Sci. Int. 1998, 95, pp 247-252. DOI: 10.1016/S03790738(98)00102-9. 14. Evrard, I.; Legleye, S.; Cadet-Taïrou, A. Int. J. Drug Policy 2010, 21, pp 399-406. DOI: 10.1016/j.drugpo.2010.03.004. 15. Pagano, B.; Lauri, I.; De Tito, S.; Persico, G.; Chini, M. G.; Malmendal, A.; Novellino, E.; Randazzo, A. Forensic Sci. Int. 2013, 231, pp 120-124. DOI: 10.1016/j.forsciint.2013.04.028. 16. Roy, E.; Richer, I.; Arruda, N.; Vandermeerschen, J.; Bruneau, J. Int. J. Drug Policy 2013, 24, pp 142-149. DOI: 10.1016/j.drugpo.2012.10.004. 17. Ensing, J. G.; Racamy, C.; Zeeuw, R. J. Forensic Sci. 1992, 37, pp 446-459. 18. Moore, J. M.; Casale, J. F.; Klein, R. F. X.; Cooper, D. A.; Lydon, J. J. Chromatog. A 1994, 659, pp 163-175. 19. Della Casa, E.; Martone, G. Forensic Sci. Int. 1986, 32, pp 117-120. 20. Esseiva, P.; Gaste, L.; Alvarez, D.; Anglada, F. Forensic Sci. Int. 2011, 207, pp 27-24. DOI: 10.1016/j.forsciint.2010.08.015. Goulart, Jr; Santos, S.; Almeida, F. V. Desenvolvimento e Validação de Métodos Cromatográficos para Quantificação de Componentes Majoritários em Amostras de Cocaína, 2012, Master's dissertation, University of Brasilia (UNb).
38
Development of an analytical methodology for chemical profile of cocaine seized in Rio de Janeiro, Brazil
Article
21. Goulart, Jr; Santos, S.; Almeida, F. V. Desenvolvimento e Validação de Métodos Cromatográficos para Quantificação de Componentes Majoritários em Amostras de Cocaína, 2012, Master's dissertation, University of Brasilia (UNb). 22. Bernardo, N. P.; Siqueira, M. E. P. B.; De Paiva, M. J. N.; Maia, P. P. Int. J. Drug Policy 2003, 14, pp 331-334. DOI: 10.1016/S0955-3959(03)00083-5. 23. D. G. De Carvalho, A. F. Mídio, Brazilian J. Pharm. Sci. 2003, 39, pp 71-76, DOI: 10.1590/S151693322003000100007. 24. De Oliveira, M. F.; Alves, J. Q.; De Andrade, J. F.; Saczk, A. A.; Okumura, L. L. Eclet. Quim. 2009, 34, pp 77-83. DOI: 10.1590/S0100-46702009000300008. 25. Magalhães, E. J.; Nascentes, C. C.; Pereira, L. S. A.; Guedes, M. L. O.; Lordeiro, R. A.; Auler, L. M. L. A.; Augusti, R.; de Queiroz, M. E. L. R. Sci. Justice 2013, 53, pp 425-432. DOI: 10.1016/j.scijus.2013.05.003. 26. de Souza, L. M.; Rodrigues, R. R. T.; Santos, H.; Costa, H. B.; Merlo, B. B.; Filgueiras, P. R.; Poppi, R. J.; Vaz, B. G.; Romão, W. Sci. Justice 2016, 56, pp 73-79. DOI: 10.1016/j.scijus.2015.11.006. 27. Lapachinske, S. F.; Okai, G. G.; dos Santos, A.; de Bairros, A. V.; Yonamine, M. Forensic Sci. Int. 2015, 247, pp 48-53. DOI: 10.1016/j.forsciint.2014.11.028. 28. Violante, N.; Quaglia, M. G.; Lopez, A.; Caroli, S. Microchem. J. 1992, 45, pp 79-89. DOI: 10.1016/0026-265X(92)90075-E. 29. Bermejo-Barrera, P.; Moreda-Piñeiro, J. J. Forensic Sci. 1999, 270, pp 44-49. 30. Liu, C.; Hua, Z.; Meng, X. Forensic Sci. Int. 2017, 276, pp 77-84. DOI: 10.1016/j.forsciint.2017.04.014.
Article
DOI: 10.30744/brjac.2179-3425.2018.5.18.i-f
31. Almeida, V. G. K.; Cassella, R. J.; Pacheco, W. F. Forensic Sci. Int. 2015, 251, pp 50-55. DOI: 10.1016/j.forsciint.2015.02.014.
32. http://tj-ma.jusbrasil.com.br/jurisprudencia/4816992/revisao-criminal-rvcr-115921999-ma [Assessed on 3rd April, 2017]. 33. http://www.akatu.org.br/Temas/Residuos/Posts/Baterias-de-carros-devem-ser-entregues-em-postosde-coleta [Assessed on 3rd April, 2017]. 34. Miller, J. C.; Miller, J. N.; Statistics and Chemometrics for Analytical Chemistry, 6th edition, Pearson Education Limited, UK, 2010. 35. United Nations Office on Drugs and Crime (UNODC). Guidance for the Validation of Analytical Methodology and Calibration of Equipment used for Testing of Illicit Drugs in Seized Materials and Biological Specimens. New York, 2009.
39
Br. J. Anal. Chem., 2018, 5 (18), 40-50 DOI: 10.30744/brjac.2179-3425.2018.5.18.40-50
Article
Download
Sensitive Voltammetric Method for Piroxicam Determination in Pharmaceutical, Urine and Tap Water Samples using an Anodically Pretreated Boron-Doped Diamond Electrode Hallyssonn Augusto Pires Rosseto1, Roberto Matos2, Roberta Antigo Medeiros2* Universidade Estadual do Oeste do Paraná (Unioeste), Centro de Engenharias e Ciências Exatas, 85903-000, Toledo, PR, Brazil 2 Universidade Estadual de Londrina (UEL), Centro de Ciências Exatas, Departamento de Química, C.P. 10.011, 86057-970, Londrina, PR, Brazil
1
Graphical Abstract
A simple and rapid voltammetric method for piroxicam (PRX) determination was developed using an anodically pretreated boron-doped diamond electrode and the square-wave voltammetric technique. Analytical curves were obtained for PRX concentrations from 0.50 to 11.0 µmol L−1, with detection limits of 0.16 µmol L−1. The proposed method was successfully applied in the determination of PRX in pharmaceutical formulations (tablets), with results similar to those obtained using a reference spectrophotometric method (at a confidence level of 95%), and in the recovery of PRX in synthetic urine and tap water samples.
Comparative to other electroanalytical methods based on different electrodes, the method yielded good results, being adequate for PRX determination in different samples with the advantage that it involves the use of a non-modified electrode. Keywords: anti-inflammatory, anodic pretreatment, BDD electrode, square-wave voltammetry, electroanalytical method. INTRODUCTION In recent decades, nonsteroidal anti-inflammatory have been among the most frequently used medicinal drugs, and in many countries can be used without medical prescription [1]. Piroxicam (PRX), 4-hydroxy-2-methyl-N-(2-pyridinyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide is a nonsteroidal anti-inflammatory drug of the oxicam class with analgesic, anti-inflammatory and antipyretic properties. It has been used in the treatment of rheumatoid arthritis, osteoarthrosis, ankylosing spondylitis and acute pain in muscular and skeletal disorders, and has been shown to be a suitable alternative for replacing other anti-inflammatory and analgesic drugs, such as aspirin, indomethacin, naproxen, ibuprofen, ketoprofen, sulindac, phenylbutazone and diclofenac in the treatment of rheumatic diseases [2, 3]. Currently, the drug PRX is classified as an emerging pollutant because it and its transformation products are continually released into the environment as a result of their manufacture, use (via excretion, mainly urine and feces) and disposal of unused and expired drugs, both directly into the domestic sewage system and via burial in landfills [4,5]. Several analytical methods for assaying PRX in pharmaceutical formulations and human body fluids have been described in the literature [6-14]. Most of these methods use chromatographic and spectrophotometric techniques in which, commonly, organic toxic solvents are used, generating high amounts of waste, the analytical frequency is low and requires prior separation steps and the analytical process is tedious. *roantigo@hotmail.com http://orcid.org/0000-0002-0751-6187
40
Sensitive Voltammetric Method for Piroxicam Determination in Pharmaceutical, Urine and Tap Water Samples using an Anodically Pretreated Boron-Doped Diamond Electrode
Article
Some electrochemical procedures also have been developed [15-23]; when compared to other types of procedure, they generally present good sensitivity, with the advantage of being relatively inexpensive, rapid, not using organic solvents and also having the possibility of analysis of colored solutions or solutions with suspended solids. Beltagi et al. [16] reported on the use of a hanging mercury drop electrode (HMDE) and square-wave voltammetry (SWV) technique to determine PRX in pharmaceuticals and human serum samples. Years later, Shahrokhian et al. [17] developed a procedure for PRX determination in pharmaceuticals and clinical preparations using a pyrolytic graphite electrode modified with a film of carbon nanoparticle– chitosan. In the same year Asadpour-Zeynali et al. [18] reported on the determination of PRX in pharmaceuticals using a chemically modified electrode based on a carbon ceramic electrode incorporated with zeolite ZSM-5 and a differential pulse voltammetric (DPV) method. Next, a procedure using a PRX-selective molecularly imprinted polymer (MIP) and carbon paste electrode was reported by Gholivand et al. [19]. The MIP embedded in the carbon paste electrode behaves as a selective recognition element and pre-concentrator agent for PRX determination. Babaei et al. [20] developed a procedure for simultaneous determination of epinephrine and PRX using a nickel hydroxide nanoparticle/multiwalled carbon nanotube (CNT) composite electrode and cyclic voltammetry (CV), DPV and chronoamperometric techniques. More recently, Gholivand et al. [21] also reported on the voltammetric oxidation of PRX at carbon paste and boehmite nanoparticle-modified carbon paste electrodes using anodic stripping DPV. Karimi-Maleh et al. [22] reported on the development of a modified N-(4-hydroxyphenyl)-3,5-dinitrobenzamide-FePt/CNT carbon paste electrode for the simultaneous determination of glutathione and PRX in hemolyzed erythrocyte, urine and pharmaceutical samples. Babaei et al. [23] developed a procedure using a glassy carbon (GC) electrode modified with a MCM-41/nickel hydroxide nanoparticle/multiwalled CNT composite as a sensor for the simultaneous determination of dopamine, PRX and cefixime in human urine and blood serum samples. In the last few years, boron-doped diamond (BDD) has been extensively investigated as electrode material for electroanalytical procedures [24-27]. It presents interesting properties which make it particularly attractive for electroanalytical applications, such as a wide working potential window in aqueous solutions, chemical inertness, corrosion resistance, inertness of the surface to adsorption of reaction products, good resistance to passivation and a low and stable background [25,27]. The electroanalytical performance of a BDD electrode, for some analytes, might depend on their surface termination (hydrogen or oxygen), which can be obtained by cathodic (hydrogen termination) or anodic (oxygen termination) electrochemical pretreatment [28]. In the literature there are many works reported on the use of cathodically pretreated BDD to determine several organic substances, such as drugs, food additives and pollutants (see e.g. [29-36]). On the other hand, in some cases, better results were attained with an anodically pretreated BDD electrode (see e.g. [37-39]). Considering the above, in this paper, we report on the influence of electrochemical pretreatment on the activity of a BDD electrode for PRX detection, as well as the optimization of a simple and rapid method for PRX determination in pharmaceutical formulations, synthetic urine and tap water samples without a previous separation step using the SWV technique. MATERIALS AND METHODS Apparatus CV and SWV experiments were performed using a PalmSens 2 (PalmSens) potentiostat/galvanostat controlled with PSTrace 4.6. A one-compartment three-electrode glass cell system was used for the 2 electrochemical measurements, with a BDD (geometric area: 0.27 cm ) as working electrode, Pt wire as −1 auxiliary electrode and an Ag/AgCl (3.0 mol L KCl) reference electrode; hereinafter all potentials are referred to this reference electrode. 41
Rosseto, H. A. P.; de Matos, R.; Medeiros, R. A.
Article The BDD films obtained from NeoCoat (Switzerland), with specified 8000 ppm boron content were prepared by the hot-filament chemical vapor deposition technique on a monocrystalline silicon (p-doped) substrate. Prior to the experiments, the BDD electrode was electrochemically pretreated by galvanostatic anodic (APT-BDD) or cathodic (CPT-BDD) polarization carried out in a 0.5 mol L−1 H2SO4 solution. For the anodic pretreatment, 100 mA cm−2 was applied for 30 s, whereas for the cathodic pretreatment, −100 mA cm−2 was applied for 180 s. After choosing the best BDD electrochemical pretreatment, the respective galvanostatic pretreatment procedure was carried out on the BDD electrode once at the beginning of every workday. The anodic pretreatment was chosen for the PRX determination, so first a cathodic pretreatment was always carried out followed by the anodic pretreatment to attain predominance of oxygen group terminations on the electrode surface. The determination of PRX by a comparative spectrophotometric method [10] was carried out using a Shimadzu UV-1601 PC spectrophotometer (at 233 nm), coupled to a microcomputer. Standard solutions at different PRX concentrations were prepared in alcoholic solution of hydrochloric acid to obtain the respective analytical curve. Reagents, supporting electrolytes and standards All reagents were of analytical grade. PRX was purchased from Sigma. Aqueous Britton–Robinson −1 (BR) buffer solution (0.04 mol L ) was used as supporting electrolyte. Buffer solutions were adjusted by −1 adding the necessary amounts of NaOH in order to obtain the appropriate pH value. The 0.05 mol L PRX stock solution was prepared in acetone, from which appropriate aliquots were diluted with the supporting electrolyte. All solutions were prepared using ultrapurified water (resistivity > 18 MΩ cm) ® supplied by a Milli-Q system (Millipore ). Preparation of pharmaceutical formulations, synthetic human urine and tap water samples The proposed method was carried out for the determination of PRX in pharmaceutical formulations, synthetic human urine and tap water samples. Two commercial samples of pharmaceutical formulations (20 mg PRX/tablet) were purchased in a local market. Ten tablets of each analyzed pharmaceutical formulation were accurately weighed and finely powdered in a mortar, transferred into a calibrated flask and the volume completed with acetone to prepare a stock solution. After that, an appropriate aliquot was diluted with supporting electrolyte. The pharmaceutical formulation samples were analyzed using the standard addition method and the PRX contents found were compared with the label values and the values obtained with the spectrophotometric comparative method. This method was then used to carry out recovery studies of PRX in different matrices: synthetic urine and tap water. The synthetic urine samples were prepared containing the majority of interferents present in real samples: 2.92 g NaCl, 1.60 g KCl, 1.10 g CaCl2.2H2O, 2.25 g Na2SO4, 1.40 g KH2PO4, 1.00 g NH4Cl and 25.0 g of urea were dissolved in water in a 1.0 L volumetric flask, as previously done by Laube et al. [40]. This solution was used immediately after its preparation. An aliquot volume of fresh synthetic urine (1.0 mL) was placed into the electrochemical cell and filled up by supporting electrolyte to 10 mL. Considering the range of the analytical curve, this solution was suitably spiked with standard solution of PRX. These recovery studies were done for two PRX concentrations (2.5 and 8.8 µmol L−1) and the standard addition method was used. The tap water sample was used for preparing the supporting electrolyte (BR buffer 0.04 mol L−1). Then, an aliquot volume of this solution (10 mL) was placed into the electrochemical cell and recovery studies were done for two PRX concentrations (2.5 and 8.8 µmol L−1). The standard addition method was also used.
42
Sensitive Voltammetric Method for Piroxicam Determination in Pharmaceutical, Urine and Tap Water Samples using an Anodically Pretreated Boron-Doped Diamond Electrode
Article
Measurement procedures All electrochemical measurements were carried out using a 10 mL electrochemical cell at room temperature (25 ± 1 °C). Deaeration of the supporting electrolyte was not necessary, since no interference from O2 was detected under the studied experimental conditions. CV and SWV were employed to investigate the electrochemical behavior and the quantification of PRX. The instrumental parameters for SWV were optimized and the respective analytical curve was obtained by adding small volumes of concentrated standard solutions of PRX to the supporting electrolyte solution (BR buffer pH 3.0). Limit of detection (LOD) values were calculated as three times the standard deviation for 10 measurements of the blank solution divided by the slope of the respective analytical curve [41]. The repeatability of the electroanalytical method was checked with intra-day (n = 10) and inter-day (n = 5) determinations for two different concentrations of PRX, for which the respective relative standard deviations (RSD) were calculated. The selectivity of the proposed method was evaluated by the addition of possible interferents present in pharmaceutical formulations and urine samples (starch, magnesium stearate, lactose monohydrate, sodium lauryl sulfate, urea, uric acid) to a standard solution containing PRX, in the concentration ratios (standard solution to interferent) of 10, 1 and 0.1. RESULTS AND DISCUSSION Electrochemical behavior of PRX and the influence of BDD electrochemical pretreatment Figure 1 presents the cyclic voltammograms (CVs) obtained for PRX using glassy carbon (GC) (dashed line) and BDD (solid line) electrodes. As can be seen, PRX presented an unique oxidation peak around 0.8 V when a BDD electrode was used; moreover, the CVs obtained evidenced irreversible electrochemical behavior for PRX, in good agreement with data previously reported in the literature [17,19]. The CV obtained for PRX using the GC electrode presented a higher capacitive current and a lower intensity faradaic current when compared with the BDD electrode, which shows the advantage of using BDD electrode for PRX determination.
Figure 1. CVs (v = 50 mV s–1) obtained for a 0.040 mol L–1 BR buffer pH 3.0 solution without and with 0.50 mmol L–1 PRX solution using a BDD electrode (solid line) and a GC electrode (dashed line).
As previously described, anodic and cathodic pretreatment on the BDD electrode can activate its surface and provide a better electrochemical response for different analytes. As can be inferred from the obtained CVs shown in Figure 2, a better-defined response for PRX oxidation is obtained when an APT-BDD electrode is used. When the BDD electrode is cathodically pretreated, the intensity of the response is lower. Clearly, the surface enrichment of oxygen terminations caused by the anodic pretreatment of the BDD electrode leads to an enhanced interaction between the electrode and the analyte [42]; this might lead to an increase in the sensitivity and, consequently, to a decrease in the detection limit.
43
Rosseto, H. A. P.; de Matos, R.; Medeiros, R. A.
Article
Figure 2. CVs (v = 50 mV s–1) obtained for a 0.040 mol L–1 BR buffer pH 3.0 solution without PRX (dot line) and with 0.50 mmol L–1 PRX solution using an APT-BDD (solid lines) or CPT-BDD (dashed line) electrode.
Effects of supporting electrolyte, pH and scan rate CV was used to investigate the effect of the supporting electrolytes [0.10 mol L−1 H2SO4, 0.040 mol L−1 BR buffer (pH 1.8) and 0.10 mol L−1 KNO3 (pH 1.8)] on the redox activity of PRX using the APT-BDD electrode [see Figure 3(A)]. The best result was obtained with aqueous 0.040 mol L−1 BR buffer (pH 1.8). The medium pH effect on the electrochemical signal of PRX was investigated. The pH of the 0.1 mmol L−1 PRX solutions was changed using BR buffer solutions in the range of 1.8 – 9.0. The results are shown in Figure 3 (B). It was observed that the maximum oxidation peak current appeared at pH = 3.0. According to this figure, a pH higher than 3.0 leads to a decrease in the peak current values. Thus, pH 3.0 was fixed by BR buffer solutions for PRX determination.
Figure 3. (A) CVs (50 mV s–1) obtained for 0.10 mmol L–1 PRX using an APT- BDD electrode in different supporting electrolytes: 0.10 mol L-1 H2SO4 (dashed line), 0.040 mol L–1 BR buffer pH 1.8 (solid line) and 0.10 mol L-1 KNO3 pH 1.8 (dashed dot line). (B) Peak current for oxidation of 0.10 mmol L–1 PRX in BR buffer at different pH, scan rate: 50 mVs−1. −1
The effect of scan rate (v) on the peak current (Ip) for 0.10 mmol L PRX was studied [see Figure 4 (A)]. Was observed that the oxidation peak shifted towards the positive direction with the increasing of scan rate, which was one of the characteristic features of the irreversible electrode reactions. A linear relationship was observed between the oxidation peak current and the square root of the scan rate [(Ip (µA) = 0.406 + 1/2 −1 1/2 44.9 v (mV s ) ; r = 0.992] [see Figure 4 (B)]. The slope of the plot of log Ip vs. log v [see Figure 4 (C)] was 0.408, which is close to the theoretical value of 0.5 (expected for an ideal reaction based on a diffusion-controlled electrode process) [43]. Hence, for the APT-BDD electrode, the electrooxidation of PRX is clearly a diffusion-controlled process. 44
Sensitive Voltammetric Method for Piroxicam Determination in Pharmaceutical, Urine and Tap Water Samples using an Anodically Pretreated Boron-Doped Diamond Electrode
Article
Figure 4. (A) CVs obtained for 0.10 mmol L–1 PRX in different scan rates (10 - 500 mVs-1) using an APT- BDD electrode in a 0.040 mol L–1 BR buffer pH 3.0; (B) linear dependence of Ip with v1/2; (C) Logarithm of the Ip as a function of the logarithm of the scan rate (v).
Optimization of the SWV parameters The most important parameters that influence the signal response obtained for PRX by SWV are the square-wave amplitude (a), square-wave frequency (f) and the increment of the staircase height (Es). When Es was changed from 1 to 6 mV, and the remaining parameters were constant (f = 60 Hz, a = 50 mV), the current peak signal increased rapidly until the value of 5 mV followed by a slow increase from 6 mV. The Es of 5 mV was chosen for the next experiments. The influence of a was studied in the range from 10 to 100 mV (remaining parameters: Es = 5 mV, f = 60 Hz). The current peak signal of PRX rapidly increased until 50 mV. Nevertheless, the peak became wider and deformed and thus the amplitude of 50 mV was chosen for the next experiments. When the frequency changed from 10 to 100 Hz (Es = 5 mV, a = 50 mV) the peak current signal increased linearly. However, the peak became wider for f above 60 Hz. Thus, f = 60 Hz was selected for all subsequent experiments. According to SWV theory [44] the number of electrons transferred in the redox process can be investigated using the relationship: ∆Ep = ∆log f = −2.3RTα/nF
(1)
Where α is the transfer coefficient and n the number of electrons involved in the redox reaction, the other terms having their usual meaning. The slope obtained from the Ep vs. log f plot was 0.0608 (results not shown); thus, by means of Eq. (1), values equal to 0.970 V were determined for αn. If the α value of is assumed as equal to 0.5, a common feature for organic molecules, these results indicate that the oxidation of PRX involves two electrons per molecule. From these results and considering the proposed PRX oxidation mechanisms in the literature [21,45] it is believed that the PRX electrochemical oxidation occurs by a two-electron mechanism (see Figure 5).
45
Rosseto, H. A. P.; de Matos, R.; Medeiros, R. A.
Article
Figure 5. Eletrooxidation reaction mechanism for PRX.
Analytical conditions for the determination of PRX using an anodically pretreated BDD electrode After these studies, an analytical curve was obtained for PRX in 0.040 mol L−1 BR buffer (pH 3.0) in the concentration range 0.50 to 11.0 µmol L−1. As can be seen in Figure 6, Ip increases proportionally with the PRX concentration (all measurements were performed in triplicate) and the corresponding calibration equation was: (Ip/μA) = −(0.06 ± 0.06) + (4.1 ± 0.4) × 105 [PRX]; r2 = 0.996
(2)
The LOD obtained was 1.6x10−7 mol L−1. The linear concentration ranges and LOD values obtained for PRX determination using different electrodes and electrochemical techniques are presented in Table I. From these data, it can be inferred that the performance attained with the APT-BDD electrode is comparatively good. Furthermore, the method proposed here involves the use of a non-modified electrode, which generally increases the analytical frequency and precision of the electroanalytical method. Then, intra- and inter-day repeatability was assessed by successive determination of PRX at different −7 −5 −1 concentrations: 9.9 x 10 and 1.1 x 10 mol L . The obtained RSD values lower than 6.5% (results not shown) attest the excellent stability and repeatability of the APT-BDD electrode response in the oxidation of PRX.
Figure 6. Square wave voltammograms for various concentrations of PRX using an APT-BDD electrode in BR buffer pH 3.0 (2-8): 0.5; 1,0; 2,5; 4,0; 6,5; 9,0; 11.0 µmol L-1. Inset: the respective analytical curve for PRX.
46
Sensitive Voltammetric Method for Piroxicam Determination in Pharmaceutical, Urine and Tap Water Samples using an Anodically Pretreated Boron-Doped Diamond Electrode
Article
Table I. Comparison of results obtained for the determination of PRX by the here-proposed method and by other electrochemical methods reported in the literature –1
-1
Electrode
Linear range (mol L )
HMDE
2.0 x 10
–10
– 2.0 x 10
–8
5.4 x 10
–11
16
5.0 x 10
–8
– 5.0 x 10
–5
2.5 x 10
–8
17
B
2.0 x 10
–7
– 2.0 x 10
–5
6.5 x 10
–7
18
C
2.0 x 10
–9
– 1.9 x 10
–7
5.0 x 10
–10
19
7.0 x 10
–7
– 7.5 x 10
–5
1.1 x 10
–7
20
5.0 x 10
–10
– 1.0 x 10
–7
1.1 x 10
–10
21
5.0 x 10
–7
– 5.5 x 10
–4
1.0 x 10
–7
22
MWCNTs-NHNPs-MCM-41/GCE
1.0 x 10
–7
– 7.0 x 10
–5
4.0 x 10
–8
23
BDD
5.0 x 10
–7
– 1.1 x 10
–5
1.6 x 10
–7
This work
A
CS-CNP-PGE CCZME
MIP–CP
D
MWCNTs-NHNPs/GCE BNP–CP
E
NHPDA/FePt/CNTs/CPE
F
G
LOD* (mol L )
Ref.
* LOD – limit of detection A basal-plane pyrolytic graphite electrode coated with a thin film of chitosan/carbon nanoparticles B carbon ceramic zeolite modified electrode C carbon Paste Electrode Modified with an MIP D nickel hydroxide nanoparticles/multiwalled carbon nanotubes composite electrode E boehmite nanoparticles modified carbon paste F N-(4-hydroxyphenyl)-3,5-dinitrobenzamide-FePt/CNTscar-bon paste electrode G multiwalled carbon nanotubes (MWCNTs), nickel hydroxide nanoparticles (NHNPs), and MCM-41 modified glassy carbon electrode.
Determination of PRX in pharmaceutical formulations, synthetic human urine and tap water samples Prior to the analysis of samples, the selectivity of the proposed method was evaluated by the addition of possible interferents (starch, magnesium stearate, lactose monohydrate, sodium lauryl sulfate, urea and uric acid) to a standard solution containing PRX at the concentration ratios (standard solution to interferent) of 10, 1 and 0.1 The current signals obtained in the presence of these possible interferents were compared with those obtained with the standard solution (data not shown) and no significant differences were found, presented Relative Errors lower than 8.6%; therefore, we could conclude that those compounds do not significantly interfere with the method proposed here. After that, the proposed method was applied to determination of PRX in pharmaceutical formulation samples. The results are reported in Table II and were compared with the results obtained with the spectrophotometric method [10]. The analytical curve obtained present a linear range concentration of 3.0 to 30.0 µmol L-1 and the calibration equation was: Abs = (1.16±0.05) × 10-3 + (2.74±0.07) × 104 [PRX]; r2 = 0.999
(3)
The representative voltammograms for determination of PRX in pharmaceutical formulations using the standard addition method are depicted in Figure 7. By analyzing the obtained results shown in Table II, one can conclude that the values obtained by the proposed method agree quite well with those obtained by the comparative method. Applying a paired t-test to the results obtained using these methods, the resulting t value (1.41) is smaller than the critical one (12.7, α = 0.05), indicating that there is no difference between the obtained results at a confidence level of 95%. 47
Rosseto, H. A. P.; de Matos, R.; Medeiros, R. A.
Article
Figure 7. Square wave voltammograms for PRX determination in pharmaceutical formulation sample by the standard addition method using an APT- BDD electrode in BR buffer pH 3.0. Concentration of PRX standard solution added: (3-6): 2.49; 4.95; 7.39 and 9.80 µmol L-1. Inset: the respective analytical curve for PRX determination in pharmaceutical formulation sample. Table II. Results obtained for PRX determination in pharmaceutical formulations by the proposed method and by spectrophotometric comparative method PRX mass per tablet / mg A
Samples
Reference Method
Proposed Method*
E (%)
A
23 ± 1
21 ± 2
-8.7
B
23 ± 1
23 ± 1
0.0
*n = 3 A Relative error (%) = 100 × (proposed method value – reference method value) / reference method value.
Then, to increase the applicability of the proposed method, samples of synthetic urine and tap water were spiked with PRX at two different concentrations and analyzed employing the standard addition method under the optimized experimental conditions. The choice of these samples was realized considering that 5% of PRX are excreted in unaltered form in urine and that it was classified as emerging pollutant [46, 47]. As can be inferred from the results shown in Table III, the novel electroanalytical method reported here yielded adequate percentage recovery values (ranging from 99 to 104%). Clearly, the method does not suffer any significant matrix interference and thus is potentially applicable in the determination of PRX in these samples kind. Table III. Results obtained for PRX determination in synthetic urine and tap water samples by the proposed methods Added (µmol L-1)
Found (µmol L-1)
Rec.* (%)
A
2.49
2.47± 0.01
99.2
B
8.80
9.21± 0.09
104
A
2.49
2.59± 0.07
104
B
8.80
8.86± 0.04
101
Samples Urine
Tap water
*(n = 3); Rec.: Recovery 48
Sensitive Voltammetric Method for Piroxicam Determination in Pharmaceutical, Urine and Tap Water Samples using an Anodically Pretreated Boron-Doped Diamond Electrode
Article
CONCLUSIONS The present study shows that the electroanalytical performance of the BDD electrode in the detection of PRX is significantly enhanced by an anodic (galvanostatic) pretreatment, which leads to a predominantly oxygen-terminated electrode surface. CV and SWV studies have shown that the PRX electrooxidation is controlled by a diffusion-electrode process and occurs by a two-electron mechanism. Then, an electroanalytical method for PRX determination using an APT-BDD electrode and SWV was developed. Optimization of the experimental parameters yielded a linear range from 0.50 to 11.0 µmol L−1 and an LOD of 0.16 µmol L−1 for PRX in BR buffer solution (pH 3.0). No absorption effects were observed on the BDD electrode, without the necessity of renovating its surface after each measurement. Furthermore, when this method was applied in the determination of PRX in pharmaceutical formulations (tablets), the results obtained were statistically equal (at a confidence level of 95%) to those obtained using a comparative spectrophotometric method. Moreover, addition-recovery determination of PRX in synthetic human urine and tap water samples yielded adequate results, indicating the potential application of the SWV method in the determination of PRX in real samples. Finally, the novel SWV method reported here is simple, relatively inexpensive and rapid, with the significant advantage that non-modified electrodes are used, which increases its analytical frequency and precision. Manuscript received Oct. 4, 2017; revised version received Dec. 4, 2017; accepted Jan. 10, 2018.
REFERENCES
1. Ungprasert, P.; Cheungpasitporn, W.; Crowson, C. S.; Matteson, E. L. Eur. J. Intern. Med. 2015, 26, pp 285-291. 2. Brogden, R. N.; Heel, R. C.; Speight, T. M.; Avery, G. S. Drugs, 1984, 28, pp 292-323. 3. Verbeeck, R. K.; Blackburn, J. L.; Loewen, G. R. Clin. Pharmacokinet. 1983, 8, pp 297-331. 4. Vera-Candioti, L.; Garcia, M. D. G.; Galera, M. M.; Goicoechea, H. C. J. Chromatogr. A, 2008, 1211, pp 22-32. 5. Hurtado-Sanchez, M. D.; Lozano, V. A.; Rodriguez-Caceres, M. I. Talanta 2015, 134, pp 215-223. 6. Baranowska, I.; Markowski, P.; Baranowski, J. Anal. Sci. 2009, 25, pp 1307-1313. 7. Sultana, N.; Arayne, M. S.; Ali, S. N. J Sep. Sci. 2013, 36, pp 3176–3183. 8. Khan, I.; Ashfaq, M.; Razzaq, S.; Mariam, I. J. Liq. Chromatogr. Relat. Technol. 2013, 36, pp 14371450. 9. Vera-Candioti, L.; García, M. D. G.; Galera, M. M.; Goicoechea, H. C. J. Chromatogr. A, 2008, 1211, pp 22-32. 10. Pereira, A.; Scheshowitsch, K.; Cruz, A.; Silva, M. A. S.; Stulzer, H. K. Visão Acadêmica, 2007, 8, pp 29-37. 11. Demiralay, E. C.; Alsancak, G.; Ozkan, S. A. J. Sep. Sci. 2009, 32, pp 2928-2936. 12. Amin, A. S.; Dessouki, H. A.; Khalil, K. M. Bull. Chem. Soc. Ethiop. 2010, 24, pp 121-126. 13. Dragomiroiu, G. T. A. B.; Cimpoiesu, A.; Ginghina, O.; Baloescu, C.; Barca, M.; Popa, D. E.; Ciobanu, A. M.; Anuta, V., T. Farmacia 2015, 63, pp 123-131. 14. Dal, A. G.; Oktayer, Z.; DoLrukol-Ak, D. J. Anal. Methods Chem. 2014, 2014, pp 1-7. 15. Acuña, J. A.; Fuente, C. D. L.; Vãzquez, M. D.; Tascón, M. L.; Sánchez-Batanero, P. Talanta, 1993, 40, pp 1637-1642. 16. Beltagi, A. M.; Abdallah, O. M.; Ghoneim, M. M. Chem. Anal. 2007, 52, pp 387-398. 49
Article
Article
Rosseto, H. A. P.; de Matos, R.; Medeiros, R. A.
17. Shahrokhian, S.; Jokar, E.; Ghalkhani, M. Microchim. Acta 2010, 170, pp 141-146. 18. Asadpour-Zeynali, K.; Majidi, M.; Zarifi, M. Cent. Eur. J. Chem. 2010, 8, pp 155-162. 19. Gholivand, M. B.; Karimian, N. Mater. Sci. Eng., C, 2011, 31, pp 1844-1851. 20. Babaei, A.; Sohrabi, M.; Afrasiabi, M., A. Electroanalysis 2012, 24, pp 2387-2394. 21. Gholivand, M. B.; Malekzadeh, G.; Derakhshan, A. A. Sens. Actuators, B, 2014, 201, pp 378-386. 22. Karimi-Maleh, H.; Tahernejad-Javazmi, F.; Ensafi, A. A.; Moradi, R.; Mallakpour, S.; Beitollahi, H. Biosens. Bioelectron. 2014, 60, pp 1-7. 23. Babaei, A.; Afrasiabi, M. Ionics, 2015, 21, pp 1731-1740. 24. Compton, R. G.; Foord, J. S.; Marken, F. Electroanalysis 2003, 15, pp 1349-1363. 25. Luong, J. H. T.; Male, K. B.; Glennon, J. D. Analyst, 2009, 134, pp 1965-1979. 26. Peckova, K.; Musilova, J.; Barek, J. Crit. Rev. Anal. Chem. 2009, 39, pp 148-172. 27. Einaga, Y.; Foord, J. S.; Swain, G. M. MRS Bull, 2014, 39, pp 525-532. 28. Salazar-Banda, G. R.; Andrade, L. S.; Nascente, P. A. P.; Pizani, P. S.; Rocha-Filho, R. C.; Avaca, L. A. Electrochim. Acta, 2006, 51, pp 4612-4619. 29. Codognoto, L.; Tanimoto, S. T.; Pedrosa, V. A.; Suffredini, H. B.; Machado, S. A. S.; Avaca, L. A. Electroanalysis 2006, 18, pp 253-258. 30. Deroco, P. B.; Vicentini, F. C.; Oliveira, G. G.; Rocha-Filho, R. C.; Fatibello-Filho, O. J. Electroanal. Chem. 2014, 719, pp 19-23. 31. Brocenschi, R. F.; Rocha-Filho, R. C.; Biaggio, S. R.; Bocchi, N. Electroanalysis 2014, 26, pp 15881597. 32. Lourencao, B. C.; Baccarin, M.; Medeiros, R. A.; Rocha-Filho, R. C.; Fatibello-Filho, O. J. Electroanal. Chem. 2013, 707, pp 15-19. 33. Janegitz, B. C.; Medeiros, R. A.; Rocha-Filho, R. C.; Fatibello-Filho, O. Diam. Relat. Mat. 2012, 25, pp 128-133. 34. Medeiros, R. A.; de Carvalho, A. E.; Rocha-Filho, R. C.; Fatibello-Filho, O. Quim. Nova 2008, 31, pp 1405-1409. 35. Mansano, G. R.; Eisele, A. P. P.; Dallâ&#x20AC;&#x2122;Antonia, L. H.; Afonso, S.; Sartori, E. R., J. Electroanal. Chem. 2015, 738, pp 188-194. 36. Sartori, E. R.; Trench, A. B.; Rocha-Filho, R. C.; Fatibello-Filho, O., J. Braz. Chem. Soc. 2013, 24, pp 1504-1511. 37. Deroco, P. B.; Medeiros, R. A.; Rocha-Filho, R. C.; Fatibello-Filho, O. Anal. Meth. 2015, 7, pp 21352140. 38. Lourencao, B. C.; Medeiros, R. A.; Thomasi, S. S.; Ferreira, A. G.; Rocha-Filho, R. C.; FatibelloFilho, O. Sens. Actuators, B, 2016, 222, pp 181-189. 39. Andrade, L. S.; de Moraes, M. C.; Rocha-Filho, R. C.; Fatibello-Filho, O.; Cass, Q. B. Anal. Chim. Acta, 2009, 654, pp 127-132. 40. Laube, N.; Mohr, B.; Hesse, A. J. Cryst. Growth, 2001, 233, pp 367-374. 41. ICH International Conference on Harmonisation, Validation of Analytical Procedures: Text and Methodology. www.ich.org 42. Brocenschi R. F.; Hammer P.; Deslouis C.; Rocha-Filho R. C. Anal. Chem. 2016, 88, pp 5363-5368. 43. Grosser, D. K., Cyclic voltammetry simulation and analysis of raction mechanisms. VCH Publisher: New York, 1994. 44. Scholz, F., Electroanalytical methods. Springer: New York, 2005. 50
Br. J. Anal. Chem., 2018, 5 (18), 51-52
Feature
Download
th
5 EspeQBrasil meeting discussed the prominent role of Chemical Speciation in Analytical Chemistry The 5th Brazilian Meeting on Chemical Speciation (EspeQBrasil 2017), held from December 10 to 13, 2017, in Águas de Lindóia (São Paulo, Brazil), brought together the principal Brazilian chemical speciation research groups.
Opening ceremony of the 5th EspeQBrasil – Photo: EspeQBrasil 2017
Dr. Lauren Nozomi Marques Yabuki, from the Institute of Chemistry of São Paulo State University (UNESP) and the vice-coordinator of the event, stated that "the 5th EspeQBrasil 2017 was an important moment for reflections and discussions on the leading role of chemical speciation within analytical chemistry". EspeQBrasil was born from a workshop on speciation analysis, held at the 29th Annual Meeting of the Brazilian Society of Chemistry (RASBQ). During this workshop, the idea of a regular discussion forum that would bring together the main Brazilian research groups involved in chemical speciation arose.
Participants during the coffee break held in the exhibitors' area Photo: EspeQBrasil 2017
Prof. Dr. Marco Aurélio Zezzi Arruda, full professor at the Institute of Chemistry of the University of st Campinas (Unicamp, SP, Brazil) led the organization of the 1 Brazilian Meeting on Chemical Speciation (EspeQBrasil 2008). Since then, EspeQBrasil has contributed considerably to chemical speciation in Brazil. 51
Feature This 5th edition of the event was organized by the Studies and Methodological Development in Biogeochemistry Group from the Center for Environmental Studies of São Paulo State University (UNESP), Rio Claro, SP, Brazil, under the coordination of Prof. Dr. Amauri Antonio Menegário. Prof. Menegário emphasized that "Brazil is experiencing an important resumption of development moment, and chemical speciation has a prominent role in guaranteeing high quality in national research, and in the development of instruments and methods to meet the recent demands and challenges".
Poster discussion session – Photo: EspeQBrasil 2017
The scientific program of the event comprised plenary lectures given by prominent scientists in the international scientific arena, presentations of studies in oral and poster sessions, as well as roundtables and mini-courses. The event attracted participants from ten states in Brazil, including researchers, university and high school teachers, postgraduate and undergraduate students, and professionals from the chemical, pharmaceutical, petrochemical, and agrochemical industries, and analytical and research laboratories. Also present at the event were renowned foreign researchers from eight different countries, including Argentina, China, Peru, Spain, and the United Kingdom. Participants also attended an exhibition showcasing the products and services of companies such as Agilent, Analitica, MixLab, and Sens, and sponsors such as Allcrom, Metrohm, and Thermo Fisher. th
During the 5 EspeQBrasil 2017, participants were able to establish and strengthen their professional and personal relationships, which are fundamental to the growth of the scientific community.
52
Br. J. Anal. Chem., 2018, 5 (18), 53-57
Feature
Download
Pittcon 2018 Presented the Latest Innovations in Laboratory Instrumentation The 69th Conference and Exposition for Analytical Chemistry and Applied Spectroscopy, the world's largest annual conference and exhibition on laboratory science, took place in the city of Orlando, Florida, USA, from February 26 to March 1, 2018. Scientists of numerous disciplines discussed current research projects with their peers and discovered the latest advances in instrumentation and technology.
The Orange County Convention Center, Orlando, FL, USA was crowded with scientists who gathered to attend the Pittcon Conference & Expo 2018.
Pittcon has always had a strong global presence, and 2018 was no exception with 25% of conferees from outside the United States from 80 countries. The top five countries by attendance were China, Canada, Japan, the United Kingdom and Germany. Attendees include lab managers, scientists, chemists, researchers and professors, from industrial, academic, and government labs. They represent an equally broad number of scientific disciplines including life science, food science, drug discovery, environmental, forensics, nanotechnology, water/wastewater, energy/fuel, agriculture and bioterrorism. The dynamic exposition floor consisted of 713 exhibitors from 33 countries, and in this edition 92 exhibitors were in Pittcon for the first time. At the exhibition, the latest innovations in instrumentation and technology used in laboratory science were presented. The NEXUS Theaters were another new addition to the exhibits. These two theaters consisted of 22 entertaining and informative presentations on a variety of topics from cannabis testing, to communicating science, to lab safety. The large interactive park area, this year called Alligator Alley, again offered attendees DemoZones, the Lab Gauntlet Challenges, LEGO® Gravity Car Racing, Virtual Reality Experiences, the Pittcon Booths and more.
Pittcon offered more than 2,000 technical presentations in 68 symposia, 10 award sessions (15 awards conferred), 14 oral sessions, 52 contributed sessions, 5 workshops and 67 poster sessions.
53
Feature Brazilian Science at Pittcon Brazil was also present at Pittcon 2018 through a symposium entitled Development of Omics Sciences in Brazil. In this symposium, the speakers addressed the progress made in proteomics, metabolomics and metallomics in Brazil, highlighting the advances made and future perspectives.
Prof. Dr. Marco Aurélio Zezzi Arruda presenting a talk at the Brazilian session of Pittcon 2018.
The Brazilian session had as speakers: Prof. Dr. Fabio Gozzo, from the Institute of Chemistry, University of Campinas; Prof. Dr. Marcelo Valle de Sousa from the Institute of Biological Sciences, University of Brasília; Prof. Dr. Marco Aurélio Zezzi Arruda, from the Institute of Chemistry, University of Campinas, and Prof. Dr. Marina Franco Maggi Tavares, from the Institute of Chemistry, University of São Paulo.
Prof. Dr. Marcelo Valle de Sousa presenting a talk at the Brazilian session of Pittcon 2018.
The Brazilian Symposium at Pittcon was sponsored by Analitica Latin America Expo and organized by NürnbergMesse Brasil, which is also responsible for the Analitica Latin America Congress and Exhibition. The 15th edition of the Analitica Latin America Expo and the 6th edition of the Analitica Latin America Congress will take place from September 24 to 26, 2019, at the São Paulo Expo Exhibition Center, São Paulo, SP, Brazil.
54
Feature For more information on Analitica Latin America 2019 visit: https://www.analiticanet.com.br/en Keynote Lectures The Wallace H. Coulter Lecture, “Analytical Science in Precision Medicine: Facing the Challenges of the 21st Century Healthcare” was presented by Dr. Jeremy K. Nicholson, the Head of the Department of Surgery and Cancer, and Director of the MRC-NIHR National Phenome Centre, Faculty of Medicine. He discussed how analytical chemistry will become increasingly important in delivering tailored healthcare solutions across the world. For example, the precise combination of microorganisms within an individual can predict health outcomes, including the risk of developing obesity and cancer prognosis. 2014 Nobel Prize winner Dr. Stefan Hell, Director at the Max Planck Institute for Biophysical Chemistry in Göttingen and for Medical Research in Heidelberg, delivered the plenary lecture with a last-minute title change to “Far-field fluorescence nanoscopy post-nobel”. He described the new concept of MINFLUX he developed to enable true molecular resolution with visible light and standard objective lenses in fluorescence microscopy. Both sessions were well attended and were followed by happy hour in Pub Pittcon. The thirty-three Conferee Networking sessions provided a unique opportunity for conferees from around the world to meet in an informal setting to discuss topics of mutual interest. The facilitator-assisted sessions discussed critical topics in areas such as environmental, biomedical, water, academia, pharmaceuticals, FDA regulations and more. Short Course The Short Course program offered an opportunity for skill-building training and continuing education for laboratory professionals. This year, ninety-three short courses were offered covering a wide variety of topics including, but not limited to, analytical methods in environmental, food and life sciences; nanotechnology; water/wastewater; petroleum and pharmaceuticals. Lab management courses are also a significant part of the program and provide critical insight into the interpretation of the requirements of regulatory aspects, global guidelines, and laboratory standards. Nearly 900 participants attended these courses and received professional development hours. Exhibitor demonstrations
Pittcon 2018 Exhibition area
The exhibition space included booths for many of the world's leading analytical instrumentation companies who presented numerous state-of-the-art technologies and innovative solutions to meet a range of analytical requirements.
55
Feature Bruker Bruker highlighted its new solution for fast analysis of edible oils by microESR. This instrument measures the oxidation profile of edible oils and provides a prediction of shelf life before the product is packaged and distributed, enabling scientists to make informed process control decisions to reduce rancidity of edible oils. Horiba At Pittcon 2018, the HORIBA group demonstrated their latest breakthrough in nanoparticle tracking analysis — ViewSizer™ 3000. By incorporating three variable light sources, this instrument is able to select the optimum conditions for any sample analysis providing high resolution particle size distribution and visualisation. Metrohm Metrohm offers a complete line of analytical laboratory and process systems for titration, ion chromatography, electrochemistry and spectroscopy. At Pittcon 2018, they demonstrated the Mira P handheld Raman spectroscope and their Vision Air Software that simplifies operation and accelerates instrument implementation for accelerated near infrared spectroscopy. Shimadzu The Shimadzu IRSpirit FTIR spectrophotometer comes with numerous built-in software macros to enable either a quick spectrum or identification of a contaminant in a complex mixture. Shimadzu also produces a range of high performance liquid chromatography systems for potency testing of cannabis. A ® single-phase liquid-gas system including their Rxi -624Sil MS column accurately determines cannabis terpene content. Thermo Fisher Thermo Fisher Scientific unveiled an expanded portfolio of analytical instruments, consumables, software and services to make technology more available to scientists worldwide, enabling faster, more informed decisions based on advanced scientific data. Among Thermo Fisher launches were the Thermo Scientific Dionex ICS-6000 high performance ion chromatography (HPIC) system, the Thermo Scientific iCAP TQs ICP-MS system, and the Thermo Scientific Chromeleon XTR Laboratory Management system. Waters We were also excited to see the launch of the new ACQUITY Arc BioSystem by Waters Corporation. This system is a versatile, iron-free, bio-inert, quaternary liquid chromatograph specifically engineered to enable the efficient transfer and improvement of bioseparation analytical methods regardless of the LC platform on which the original method was developed. Pittcon Today Excellence Awards The second annual Pittcon Today Excellence Awards recognized ingenuity and innovation at this year's exposition. Finalists were selected by a blue chip panel of experts, including leading voices in academia, industry, and trade publications, who evaluated exhibitor entries based on ingenuity, creativity, implementation and outcomes. The principal criterion being the product's projected impact on the industry and the wider public. The awards recognize innovations at the exposition and offer a new channel for exhibitors to showcase their scientific advancements. From portable instruments, to wireless temperature sensing, to time-saving innovations, judges evaluated all types of scientific innovations and selected finalists out of a diverse pool of submissions. The prestigious awards were presented at each exhibitor booth recognizing gold, silver and bronze winners across the three sales categories.
56
Feature Award recipients include: Less than $10,000,000 in sales category: Ø GOLD - Gate Scientific, Inc. - Wireless smartSENSE Stirbar Ø SILVER - RotaChrom Technologies.- RotaChrom rCPC and iCPC Ø BRONZE - Axcend Corporation - Axcend Foco LC $ 10 - $ 100,000,000 in sales Category: Ø GOLD - B&W Tek - STRaman® Ø SILVER - Metrohm- 946 Portable VA Analyzer Ø BRONZE - CEM Corporation - EDGE Greater than $100,000,000 in sales category: Ø GOLD - HORIBA Scientific – Duetta Ø GOLD - Xylem, OI Analytical - 1080 Combustion Total Organic Carbon Analyzer Ø SILVER - Fluid Imaging Technologies, Inc. - FlowCam Nano Ø BRONZE - Shimadzu Scientific Instruments - IRSpirit
57
The robust technical program offers the latest research in more than 2,000 technical presentations covering a diverse selection of methodologies and applications.
Pittcon also offers more than 100 skill -building short courses in a wide range of topics
Opportunity to network with colleagues.
What is Pittcon? Pittcon is the worldâ&#x20AC;&#x2122;s leading annual conference and exposition on laboratory science. Pittcon attracts attendees from industry, academia and government from over 90 countries worldwide.
Br. J. Anal. Chem., 2018, 5 (18), 59-61
Sponsor Report
Download
This section is dedicated for sponsor responsibility articles.
Determination of Mercury in Animal Feed by Direct Mercury Analysis (DMA) - A Simple Analysis Bruno M. Siqueira* Nova Analítica Importação e Exportação, São Paulo, SP, BR
An elemental method for determining the Hg content in animal feed samples was developed in order to comply with Brazilian food contamination regulations. The methodology chosen was sample thermal decomposition followed by atomic absorption determination. The low limits of allowed mercury forces many laboratories to use cold vapor with atomic absorption or ICP OES (inductively coupled plasma optical emission spectrometry), which are challenging techniques. Keywords: Food and feed safety, mercury determination, thermal decomposition. INTRODUCTION Mercury exists in the environment in metallic, inorganic, and organic forms. Metallic and inorganic mercury are released into the air from industrial activities (including mining), and is deposited in water, soil, and sediment, where it can be transformed into methylmercury. There have been two major incidents involving mercury intoxication: one in 1950, where an acetaldehyde-producing factory dumped tailings containing methylmercury in Minamata Bay (Japan), resulting in more than 100 deaths due to the consumption of contaminated fish; the second was in 1970, due to consumption of bread that had been made with methylmercury-based fungicides in Basra (Iraq). Following these incidents, the use of organomercury in industry and agriculture has been banned [1,2]. -1 Brazilian legislation allows a maximum concentration of 0.05 mg kg of Hg in any food, however, for fish the maximum concentration is 0.5 mg kg-1 (prey) and 1.0 mg kg-1 (predator). The maximum limits for animal feed are the same as for food [3,4]. Mercury content in food is usually low, making its determination difficult. Many laboratories use cold vapor with atomic absorption or ICP OES to analyze mercury. However this kind of method requires sample preparation, dilutions, and reagents. In this study, we propose a method using thermal decomposition followed by atomic absorption determination to analyze mercury without the need for sample preparation or reagents. Table I. Maximum mercury limits permitted in food samples according to Brazilian legislation ANVISA* PNCRC** -1 -1 (mg kg ) (mg kg ) predator fish
prey fish
catch fish
0.5
1.0
0.03
farming fish 1.0
shrimp 0.5
*National Agency of Sanitary Surveillance **National Plan for the Control of Residues and Contaminants
MATERIALS AND METHODS This study was conducted in the Elemental Analysis Laboratory, Nova Analitica ltda. The samples (animal feed from different sources) were obtained from a Nova Analitica costumer. All the material used in the analysis was decontaminated by washing with a neutral detergent, rinsing with distilled water, and soaking in a diluted 2% HCl (v/v) bath for 4 h. After this, the material was intensively rinsed with ultrapure water deionized water with a resistivity of ≥18.2 MΩ cm. The sample was then allowed to dry. *bruno.menezes@novanalitica.com.br
59
Determination of Mercury in Animal Feed by Direct Mercury Analysis (DMA) - A Simple Analysis
Sponsor Report All the solutions were prepared using ultrapure deionized water in a Veolia™ Element system. High purity 65% HCl (v/v) was obtained from a DuoPur Acid Purification System (Milestone, Bergamo, Italy). Hg stock solution (999±3 mg L−1) from SpecSol (São Paulo, SP, Brazil) was used to prepare the standard solutions. Quartz sample boats (Milestone, DMA 8347) were used for the calibration curves. The Certified Reference Material Nist 1515 (Apple Leaves Certified Reference Material for trace metals) was used to test the accuracy of the method. The samples were weighed on a digital analytical balance to four decimal places to the nearest 0.1 mg (Mettler Toledo, Columbus, Ohio, EUA). A Direct Mercury Analyzer (DMA-80, Milestone, Bergamo, Italy) was used to determine the total Hg in animal feed. The DMA-80 technology is based on drying a sample followed by thermal decomposition, and the electrothermal atomization of mercury. There are two possible sample boats that can be used: quartz and nickel. We used quartz sample boats. An internal thermocouple (ATC) sensor controlled the drying/decomposition temperature. Hg reduction was performed using a catalyst system (Milestone, DMA 8333). After this, Hg vapor was trapped in a gold amalgamator system (Milestone, DMA 8134). A gold amalgamator was used to selectively trap and pre-concentrate the Hg from the flow of decomposition products. Hg determination was carried out by atomic absorption spectrometry at 253.65 nm after the thermal desorption of Hg trapped in the amalgamator. This system contains a tri-cell spectrophotometer, allowing the instrument to work at low concentrations. The peak height was used for signal evaluation. The working parameters used to determine Hg in animal feed are described in Table II. Table II. Working parameters for Hg determination in animal feed Parameter Setting Maximum start temperature (°C)
250
Drying temperature (°C)
300
Drying time (s)
100
Decomposition temperature (°C)
700
Decomposition time (s)
180
Amalgamator heating time (s)
12
Signal recording time (s)
24
Purge time (s)
30
Cuvette temperature (°C)
120
Cuvette type
quartz
Compressed air pressure (bar)
3 -1
Compressed air flow rate (mL min )
100
Sample mass (mg)
100
The precision of the method was verified by the analysis of the certified reference material of apple leaves (NIST 1515). This material contained 44 ± 4 µg kg-1 of mercury. RESULTS AND DISCUSSION Table III describes the calibration curve for the three absorbance cells. Table III. Calibration curve for the three absorbance cells
60
Cell
Mass (ng of Hg)
Regression equation
Cell 0
0; 0.5; 1; 3
y=0.1708 Hg–0.007 Hg
Cell 1
0; 0.5; 1; 3; 5; 10; 15
y=0.0633 Hg–0.0009 Hg
Cell 2
25; 52; 156; 1004
y=9.6592*10 –1.9265*10 Hg
R 2
-4
-7
2
0.9999
2
0.9999 2
0.9999
Siqueira, B. M.
Sponsor Report
The linearity was more than 0.999. This result was satisfactory for our analysis. The mercury concentrations in each sample and the certified reference material are given in Table IV. Table IV. Mercury concentration results Mercury concentration -1 observed (µg kg )
Expected mercury concentration -1 (µg kg )
1716897
1.29
≤ =100
1715001
2.30
≤ =500
1715609
3.21
=1500 ≤
1717366
1.19
≤ =100
1717189
756.84
≤ =300
Nist 1515
46.58
44 ± 4
Water 1
0.42
------
Water 2
4.58
5
Sample
The “water 1” sample was prepared as a sample blank. “Water 2” was a standard prepared with a 5 µg kg concentration of mercury. -1
CONCLUSIONS The calibration curves determined were satisfactory, showing linearity above 0.999. The analysis of mercury in the samples showed good accuracy, since the results of the certified reference material were within the error range presented by Nist. The Hg analyzer, DMA-80, was efficient for the determination of mercury in human and animal feed samples, with sufficient sensitivity for the analyses and excellent accuracy. The DMA-80 was easy to use, since it did not require sample preparation, a daily calibration curve, or reagents as in an atomic absorption and ICP OES instrument. REFERENCES
1. Baeyens, W. Trends Anal. Chem. 1992, 11, pp 245–254. 2. Clarkson, T. W. Environ. Health Perspect. 2002, 110, pp 11–23. 3. http://www.agricultura.gov.br/portal/page/portal/Internet-MAPA/pagina-inicial/pncrc [Accessed 11 January 2018]. 4. http://www.anvisa.gov.br/alimentos/legis/especifica/contaminantes.htm [Accessed 11 January 2018].
This sponsor report is the responsibility of Nova Analítica Milestone Srl.
61
Br. J. Anal. Chem., 2018, 5 (18), 62-67
Sponsor Report
Download
This section is dedicated for sponsor responsibility articles.
Accurate Determination of Arsenic and Selenium in Environmental Samples using the Thermo Scientific iCAP TQ ICP-MS Marcus Manecki1, Simon Lofthouse2, Philipp Boening3 and Shona McSheehy Ducos1 1 Thermo Fisher Scientific, Bremen, Germany 2 Thermo Fisher Scientific, Hemel Hempstead, UK 3 Institute of Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University of Oldenburg, Oldenburg, Germany The goal of this work is to demonstrate the accurate determination of arsenic and selenium in sediments and rocks that contain elevated levels of rare earth elements using triple quadrupole ICP-MS. Keywords: Arsenic, interference removal, REE, rock, selenium, soil, sediment. INTRODUCTION Due to the impact arsenic and selenium can have in the environment at low levels, as a toxin or essential nutrient respectively, it is important to be able to quantify them accurately. Selenium for example is an essential element that is necessary for normal thyroid function and due to its antioxidant properties, is associated with several health benefits. Diseases associated with selenium deficiency such as Keshan disease and symptoms of hypothyroidism, are most commonly found in areas where levels of selenium in soil are particularly low. Supplementation as a remedy is common practice and is not isolated to humans. Understanding where soil selenium deficiencies occur for example supports the correct supplementation of cattle grazing in those areas to prevent white muscle disease (a cattle specific selenium deficiency disease). Arsenic on the other hand, in its inorganic forms (the most common forms found in ground water and soils) is classified as carcinogenic. Arsenic can be found at natural, elevated levels or highly enriched in ground waters (e.g. in Bangladesh) and in soils from irrigation with arsenic contaminated ground water. In this case, accurate analysis of arsenic is key to understanding whether crops, such as rice grown in these areas could contain an elevated level of arsenic and be a potential risk for consumption. In addition to assessing the exposure implications of these elements, their accurate analysis is vital to understanding their geochemical cycling processes and impact on the environment. Analysis of these two elements by ICP-MS is challenging due to multiple spectral interferences, and becomes especially challenging in the presence of high amounts of rare earth elements (REEs) such as dysprosium, gadolinium, neodymium, samarium or terbium due to the formation of doubly charged ions. These doubly charged REEs lead to false positive results on arsenic and selenium and as such lead to incorrect conclusions and actions based on that data. Triple quadrupole (TQ) ICP-MS offers improved interference removal for such challenging applications through the use of selective reaction chemistry to produce higher mass ions, which can either mass shift analytes into an interference free region of the mass spectrum or mass shift interferences away from analytes. This application note evaluates the efficiency of TQ-ICP-MS measurement modes and compares them to single quadrupole (SQ) ICP-MS measurement modes with the Thermo Scientific™ iCAP™ TQ ICP-MS for the quantification of arsenic and selenium in the presence of REEs. To test the robustness and the accuracy of the approach, two samples, a deep sea sediment and a geochemical reference standard, were analyzed under optimal conditions. 62
Accurate Determination of Arsenic and Selenium in Environmental Samples using the Thermo Scientific iCAP TQ ICP-MS
Sponsor Report
MATERIALS AND METHODS Instrumentation An iCAP TQ ICP-MS was used to analyse all samples. The system was configured with a high matrix interface (Table I) for improved handling of the high amounts of total dissolved solids (TDS) encountered in the samples and a 200 μL min-1 free aspirating, glass, concentric nebulizer due to the limited volume of digested sample. Four different measurement modes were evaluated: SQ-STD – single quadrupole mode with no collision/reaction cell (CRC) gas. SQ-H2 – single quadrupole mode with CRC pressurized with pure hydrogen as a reaction gas. SQ-KED – single quadrupole mode with CRC pressurized with helium as a collision gas and Kinetic Energy Discrimination (KED) applied. TQ-O2 – triple quadrupole mode with CRC pressurized with oxygen as a reaction gas, Q1 set to analyte mass (M+) and Q3 set to product ion mass (MO+). All parameters within each of the measurement modes were defined automatically by using the autotune procedures provided in the Thermo Scientific™ Qtegra™ Intelligent Scientific Data Solution (ISDS) Software. The autotune functionality ensures that plasma and interface related settings, such as nebulizer flow and extraction lens voltage are automatically applied across all associated measurement modes so that the sample is processed in exactly the same way in the plasma, independent of the CRC and quadrupole settings. Details about the settings used for the different modes are shown in Table I. Table I. Instrument parameters for all measurement modes Parameter
Value
Nebulizer Spraychamber Injector Interface RF Power Nebulizer Gas Flow
MicroMist quartz nebulizer 0.2 mL min , free aspirating Quartz cyclonic spraychamber cooled to 2.7 °C 2.5 mm id, quartz High Matrix (3.5 mm) insert, Ni cones 1550 W -1 1.04 L min
Modes Mass shift applied Mass shift over x mass units Gas Flow CR Bias Q3 Bias Scan Settings
-1
SQ-STD No -2 -1
SQ-H2
SQ-KED
TQ-O2
No No Yes 16 -1 -1 -1 9.0 mL min 4.65 mL min 0.35 mL min -7.55 -21 V - 7.0 V -12 V -18 V -12 V 0.2 s dwell time per analyte, 10 sweeps
The method development assistant in the Qtegra ISDS Software, Reaction Finder, automatically selects the best mode to use for the analyte measurements. In this evaluation exercise, in which the effectiveness of different measurement modes for the same analyte was investigated, replicate analytes were added and the measurement modes selected manually. The formation of doubly charged ions and the resulting interferences in ICP-MS are known issues. There are several ways to mitigate these interferences on the analyte signals, including: · Interference correction equations · Tuning of the instrument to reduce formation of doubly charged ions within the plasma · Mass shift reactions that move the analyte of interest to a different m/z Many laboratories prefer to avoid the approach of using interference correction equations as it is possible that due to small daily changes in plasma conditions, they need to be calculated or checked on a daily basis to verify their accuracy. Mass shift reactions show promise but have limitations with SQ-ICP-MS due to the complex mixture of ions in the CRC that can cause other potential interferences. With TQ-ICPMS, the pre-selection of the mass of interest in Q1 enables a more controlled reaction for the analytes and emoves interferences that could still be problematic in SQ-ICP-MS. 63
Sponsor Report
Manecki, M.; Lofthouse, S.; Boening, P.; Ducos, S. McS.
The Reaction Finder tool selects TQ-O2 mode automatically for 75As and 80Se. To be able to compare different modes and the results for different isotopes, the same measurement mode was also selected for 78 82 Se and Se. This mode uses pure O2 in the CRC to create oxide ions of the arsenic and selenium isotopes. Arsenic was measured at m/z 91 as 75As16O and the selenium isotopes 78Se, 80Se and 82Se were measured at m/z 94 as 78Se16O, at m/z 96 as 80Se16O and at m/z 98 as 82Se16O respectively. Figure 1 demonstrates how Q1 (when set to the analyte mass), effectively removes the singly charged 91 94 75 REEs and any ions that would eventually interfere with the product ions, such as Zr and Mo for As and 78 91 + 94 + Se respectively. Q2 (the CRC) is filled with O2 and creates the product ions [AsO] and [SeO] for 75As and 78Se respectively. In Q3, any remaining doubly charged REE are rejected and the product ion is isolated for measurement.
Figure 1. TQ mass shift modes for arsenic and selenium. Sample preparation Calibration standards of arsenic and selenium at concentrations of 0.2, 0.5, 1, 2 and 5 μg L-1 were prepared by diluting the appropriate volume of single element standards (SPEX CertiPrep) in a mixture of 2% (v/v) HNO3 and 2% (v/v) methanol (MeOH) (OPTIMA LC/MS grade, Fisher Scientific). Mixtures of REE for interference evaluation were prepared by diluting appropriate volumes of the single element standards (SPEX CertiPrep) dysprosium, gadolinium, neodymium, samarium and terbium in 2% (v/v) HNO3 / 2% (v/v) MeOH. The final solution contained 1 mg L-1 of each REE. Approximately 35 mg of a marine sediment sample, collected from the deep Pacific Ocean (supplied by the University of Oldenburg, Germany) and 50 mg of the andesite reference standard AGV-1 (United States Geological Survey) were weighed and treated in closed PTFE vessels with concentrated HNO3 (1 mL, OPTIMA grade, Fisher Scientific) overnight to oxidize any organic matter (if present). In the next step, concentrated HF (1.5 mL, OPTIMA grade, Fisher Scientific) and HClO4 (1.5 mL, OPTIMA grade, Fisher Scientific) were added and the vessels then heated in a hot block for 12 h at 180 °C. After digestion, the acids were evaporated on a hot plate at 180 °C to near dryness. The residues were re-dissolved, fumed off three times with 6 N HCl to near dryness and finally taken up in 10 mL 1 N HNO3. Prior to analysis, both samples were further 1:10 diluted with 1% (v/v) HNO3 / 2% (v/v) MeOH. The dilution protocol resulted in final TDS levels of 500 ppm for AGV-1 and 348 ppm for the sediment sample. -1 Lutetium was added at a concentration of 1 μg L as an internal standard to all blanks, standards and samples prior to analysis. The use of methanol (or other suitable carbon source) is important in the analysis of arsenic and selenium due to the effect of carbon enhancement in the plasma which increases the ionization of both elements. This will correct for over recovery in the case of external calibration and also leads to higher sensitivity and improved detection limits. 64
Accurate Determination of Arsenic and Selenium in Environmental Samples using the Thermo Scientific iCAP TQ ICP-MS
Sponsor Report
RESULTS AND DISCUSSION External calibrations for arsenic and selenium in the range 0.2 to 5 μg L-1 show excellent linearity and LODs of 0.17 ng L-1 and 2.02 ng L-1 for 75As (Figure 2, left) and 78Se (Figure 2, right) respectively, when using TQ-O2 mode. The carbon enhancement effect of methanol in the samples is seen as an approximate 2-fold increase in sensitivity for both analytes, compared to typical sensitivities without methanol.
Figure 2. Screenshots from Qtegra ISDS Software. Calibration curves for 75As measured as 91[AsO]+ (left) and 78Se measured as 94[SeO]+ (right) in TQ-O2 mass shift mode.
To demonstrate the efficiency of interference removal with TQ-O2 mass shift mode, it was compared to three different SQ modes: SQ-STD (no gas), SQ-H2 and SQ-KED (He gas). The background equivalent concentrations (BECs) of arsenic and the 3 isotopes of selenium (at masses 78, 80 and 82) were determined in a solution containing 1 mg L-1 each of the REEs dysprosium, gadolinium, neodymium, samarium and terbium (to give a total REE concentration of 5 mg L-1) (Figure 3).
-1
Figure 3. BECs of arsenic and selenium isotopes in a 5 mg L REE solution using four different measurement modes. The y-axis for the BEC is reported in logarithmic scale for clarity. The BEC of 80Se for SQ-STD mode is not reported because of the large interference from 40Ar. In SQ-STD mode, the BEC for 75As was 9.7 μg L-1 and for the selenium isotopes all BECs were between 23 and 142 μg L-1 due to the non-filtered doubly charged interferences from the REEs. While SQ-KED is a powerful tool for the removal of polyatomic interferences, it suffers from an increased transmission of doubly charged ions relative to other ions in the mass range where these doubly charged ions are detected, due to their higher kinetic energy. This is reflected in the increased BEC. Although SQ-H2 mode is effective for removing argon based polyatomic interferences, it is not suitable for removing doubly charged -1 interferences resulting in BECs in the single to double digit μg L range. 65
Manecki, M.; Lofthouse, S.; Boening, P.; Ducos, S. McS.
Sponsor Report TQ-O2 mode showed the lowest BECs for all of the isotopes investigated. In this mode, BECs of 30 ng L for 75As and 23, 32 and 60 ng L-1 for 82Se, 80Se and 78Se respectively, were achieved. -1 -1 To evaluate the accuracy of the TQ-O2 mode, the 5 mg L REE solution was spiked with 1 μg L arsenic and selenium, and spike recoveries were determined (Figure 4). All recoveries were within 99 to 102% of the spiked value, demonstrating good accuracy for the method. -1
Figure 4. Spike recoveries of 1 μg L-1 arsenic and selenium from a 5 mg L-1 REE solution in TQ-O2 mode.
TQ-O2 mode provides the best BECs for arsenic and selenium in a complex matrix so this mode was applied for the analysis of two different samples, a certified standard (AGV-1) and one deep sea sediment sample. AGV-1 is an andesite geochemical reference standard, with principal matrix components of silicon, aluminum and iron and with gadolinium at 5 μg g-1, samarium at 5.9 μg g-1, dysprosium at 3.6 μg g-1 and neodymium at 33 μg g-1. After digestion and dilution of the raw material the concentrations of gadolinium, -1 samarium, dysprosium and neodymium in the analyzed sample were 2.5, 2.95, 1.8 and 16.5 μg L , respectively. The deep sea sediment was collected as part of a collection of samples along a transect in the deep Pacific Ocean as part of an independent study. Although not certified, the sediment is expected to contain elevated levels of REEs. The quantitative data for arsenic and selenium measured in the AGV-1 CRM and the deep seas -1 sediment are shown in Table II. The measured concentration of 0.446 μg L As in the diluted AGV-1 sample corresponds to a recovery of around 100% of the certified value. The limit of quantification (LOQ) was calculated by multiplying the standard deviation of the blank signal by a factor of 10, then dividing this result by the slope of the calibration. Both samples were also spiked with 1 μg L-1 of arsenic and selenium after the digestion and dilution steps to determine analyte recovery and accuracy of the method. The spike recoveries for arsenic and all selenium isotopes (93-98%) demonstrate good accuracy for arsenic and selenium determination in these complex samples (Table III). The internal standard recovery of lutetium (measured as 175Lu16O) was in the range of 90-107% throughout the sample analysis when compared to the calibration blank.
66
Accurate Determination of Arsenic and Selenium in Environmental Samples using the Thermo Scientific iCAP TQ ICP-MS
Sponsor Report
Table II. Quantitative data for arsenic and selenium in AGV-1 and a deep sea sediment using TQ-O2 mode (calculated back to the solid and reported in μg g-1). AGV-1
Content in original -1 sample (μg g )
Certified -1 content (μg g )
Recovery
75
As
0.892
0.88
101%
78
Se
< LOQ
-
-
Deep Sea Sediment 75
As
1.303
-
-
78
Se
0.109
-
-
Table III. Spike recovery of arsenic and selenium in AGV-1 and the marine sediment sample using TQ-O2 mode. Both samples were spiked with 1 μg L-1 of arsenic and selenium after digestion and 1:10 dilution. AGV-1
Measured concentration -1 (μg L )
Measured concentration -1 in spiked sample (μg L )
Spike recovery (%)
75
As
0.446
1.392
94.6
78
Se
< LOQ
0.939
93.4
80
Se
< LOQ
0.935
93.1
82
Se
< LOQ
0.944
93.6
Measured concentration -1 (μg L )
Measured concentration -1 in spiked sample (μg L )
Spike recovery (%)
Deep Sea Sediment 75
As
0.454
1.429
97.6
78
Se
0.038
1.014
97.6
80
Se
0.037
1.016
97.9
82
Se
0.037
1.001
96.4
CONCLUSION The iCAP TQ ICP-MS was used to measure trace levels of arsenic and selenium in complex environmental matrices. The measured concentration for arsenic in the certified geological material was in agreement with reference values and the spike recoveries for both arsenic and selenium in both samples were determined in the range 93-98%. The TQ-O2 mode shows the lowest BECs for arsenic and selenium in the presence of high concentrations of REEs when compared to the other analysis modes. The TQ-O2 mode is an ideal mode for interference removal in rocks, soil and sediment samples where high REE concentrations can be expected. The Reaction Finder tool offers the user the ability to set up methods easily by automatically determining the optimum measurement modes for the analysis and reduces the time spent on the daily method set-up.
REFERENCE 1. http://crustal.usgs.gov/geochemical_reference_standards/andesite1.html
This sponsor report is the responsibility of Thermo Fisher Scientific.
67
Br. J. Anal. Chem., 2018, 5 (18), 68-80
Sponsor Report
Download
This section is dedicated for sponsor responsibility articles
Optimized GC-MS Solution for Semivolatiles (SVOC) Analysis in Environmental Samples in Compliance with the U.S. EPA Method 8270D Richard Law1, Cristian Cojocariu1, Daniela Cavagnino2 1 Thermo Fisher Scientific, Runcorn, UK 2 Thermo Fisher Scientific, Milan, Italy This Sponsor Report shows how a single quadrupole GC-MS system can meet Method 8270D requirements with the extended dynamic range detection system. The working method range was shown to be 0.2–200 ppm using the same column. A unique technology for speeding up the routine maintenance operations, saving the time typically required to vent the MS system and re-establish the vacuum conditions is discussed. Keywords: GC-MS, Helium Saver, EPA 8270, SVOC, SVOA, semivolatile organic compound, BNA, base neutral acids, organic contaminants. INTRODUCTION The United States Environmental Protection Agency (U.S. EPA) released the first Semivolatile Organic Compounds (SVOC) method by Gas Chromatography-Mass Spectrometry (Method 8270) at the end of 1980. It is a common method used in almost all environmental laboratories looking to analyze semivolatile organic compounds in extracts prepared from many types of solid waste matrices, soils, air sampling media, and water [1]. Since then, single quadrupole mass spectrometers have become much more sensitive and the source fragmentation has changed. Many original assumptions [2] about the origin and nature of the ion species have proven to be wrong or require correction, while the new generations of the mass spectrometers have proven to provide more response in the high-mass region [3], resulting in adjustment of the tuning criteria to be met [4]. To adjust to these changes, the EPA has changed the ion abundance criteria for the passing of DFTPP ion ratio criteria in EPA Method 8270D. This report shows how the Thermo Scientific™ ISQ™ 7000 single quadrupole GC-MS system can meet Method 8270D requirements with the extended dynamic range detection system. The working method range was shown to be 0.2–200 ppm using the same column. Particular attention has been posed on maximizing the uptime of the instrument, as required by highthroughput laboratories. The innovative Thermo Scientific™ NeverVent™ technology available on the ISQ 7000 GC-MS system is a unique solution for speeding up the routine maintenance operations, saving the time typically required to vent the MS system and re-establish the vacuum conditions. The new Thermo Scientific™ Instant Connect Helium Saver Injector was also assessed in this application to show that significant financial costs savings can be realized throughout the lifetime of a GC-MS instrument without compromising the instrument's performance. MATERIALS AND METHODS The method was tested on five ISQ 7000 GC-MS systems equipped with the Thermo Scientific™ ExtractaBrite™ ion source to assess method transferability and instrument-to-instrument variability. Both ranges (0.2–50 ppm and 2–200 ppm) were validated using the Instant Connect Helium Saver Injector (P/N 19070013) and the Thermo Scientific™ Instant Connect Split-Splitless (SSL) Injector module (P/N 19070010). The column used was a Thermo Scientific™ TraceGOLD™ TG-5MS GC Column with 5 m guard, 30 m × 0.25 mm × 0.25 μm (P/N 26098-1425). A Thermo Scientific™ Injection Port Deactivated 68
Optimized GC-MS solution for semivolatiles (SVOC) analysis in environmental samples in compliance with the U.S. EPA Method 8270D
Sponsor Report
Liner 4 mm ID × 105 mm (P/N 453A1925) was selected for the Split-Splitless injection port. The ISQ 7000 GC-MS system operated in full-scan mode and the Thermo Scientific™ Chromeleon™ Chromatography Data System (CDS) software was used to acquire, process, and report data. The operating parameters for the Thermo Scientific™ TRACE™ 1310 GC system are reported in Table I(a) (splitless method, range 0.2–50 ppm) and Table I(b) (split method, range 2–200 ppm). The ISQ 7000 single quadrupole MS operating conditions are detailed in Tables II(a) and II(b). Table I(a). TRACE 1310 GC system parameters for splitless method
Table I(b). TRACE 1310 GC system parameters for split method
Injection Volume (μL)
1.0
Injection Volume (μL)
1.0
Liner
Deactivated Splitless Liner
Liner
Deactivated Splitless Liner
Inlet Temp (°C)
Inlet Temp (°C)
310
Inlet Module and Mode
SSL in Split Mode
Splitess Time (min)
270 SSL in Surge Splitless at 345 kPa for 0.6 min 0.6
Split Flow (mL/min)
50
Inlet Module and Mode
Oven Temperature Program
Split Ratio 10:1 Split Flow (mL/min) 15 He, 1.5 Carrier Gas (mL/min) Oven Temperature Program
Initial Temperature 1 (°C)
35
Initial Temperature 1 (°C)
35
Hold Time (min)
2.25
Hold Time (min)
2.25
Rate (°C/min)
25
Rate (°C/min)
25
Temperature 2 (°C)
100
Temperature 2 (°C)
100
Hold Time (min)
0.1
Hold Time (min)
0.1
Rate (°C/min)
30
Rate (°C/min)
30
Temperature 3 (°C)
280
Temperature 3 (°C)
280
Hold Time (min)
0.1
Hold Time (min)
0.1
Rate (°C/min)
10
Rate (°C/min)
10
Temperature 4 (°C)
320
Temperature 4 (°C)
320
Hold Time (min)
5.00
Hold Time (min)
5.00
Table II(a). ISQ 7000 Single Quadrupole MS parameters for splitless method
Table II(b). ISQ 7000 Single Quadrupole MS parameters for split method
Transfer Line Temp (°C)
300
Transfer Line Temp (°C)
310
Ion Source
ExtractaBrite
Ion Source
ExtractaBrite
Ion Source Temp (°C)
300
Ion Source Temp (°C)
300
Ionization Mode
EI
Ionization Mode
EI
Electron Energy (eV)
70
Electron Energy (eV)
70
Acquisition Mode
Full-scan
Acquisition Mode
Full-scan
Scan Range (m/z)
35–500
Scan Range (m/z)
35–500
Emission Current (mA)
10
Emission Current (mA)
15
Dwell Time
0.1
Dwell Time
0.1
Tuning for DFTPP The ISQ 7000 MS system was tuned with a built-in EPA 8270D specifically designed tune (DFTPP Tune). This assures fulfillment of all method requirements in terms of ion abundance criteria. A tune verification DFTPP solution was injected to verify that the ISQ 7000 GC-MS system met the tuning requirements shown in Figure 1. Chromeleon CDS software has a dedicated reporting package for environmental laboratories, and automatically reports tune evaluation performance with a Pass/Fail Indicator (Table III). 69
Law, R.; Cojocariu, C.; Cavagnino, D.
Sponsor Report
Figure 1. Acquired DFTTP mass spectrum using the ISQ 7000 single quadrupole GC-MS system operated in full-scan at 70 eV ionization energy.
Table III. DFTPP spectrum check for ion abundance criteria Eval Mass (m/z)
Ion Abundance Criteria
Measured % Relative Abundance 20.7
Criteria Pass/ Fail Pass
51
Greater than or equal to 10% AND less than or equal to 80% of Base Peak
68
Less than 2% of m/z 69
0.7
Pass
70
Less than 2% of m/z 69
0.5
Pass
127
Greater than or equal to 10% AND less than or equal to 80% of Base Peak
29.4
Pass
197
Less than 2% of m/z 198
0.1
Pass
198
Greater than 50% AND less than or equal to 100% of Base Peak
57.5
Pass
199
Greater than or equal to 5% AND less than or equal to 9% of m/z 198
5.9
Pass
275
Greater than or equal to 10% AND less than or equal to 60% of Base Peak
17.2
Pass
365
Greater than 1% of m/z 198
4.6
Pass
441
Greater than 0% AND less than 24% of m/z 442
17.4
Pass
442
Greater than 50% AND less than or equal to 100% of Base Peak
100.0
Pass
443
Greater than or equal to 15% AND less than or equal to 24% of m/z 442
18.1
Pass
Standard and sample preparation Standards (Restek 8270 MegaMix Cat. No. 31850, AccuStandard Internal Standard Cat. No. Z-014J, AccuStandard Surrogate Cat No. M-8270-SS) were prepared in methylene chloride, and the internal standards were spiked at a concentration of 5 ppm for both the splitless and split methods. Spiking the range of 0.2 to 200 ppm with the same concentration of internal standards eliminated the necessity of preparing two different sets of calibration standards. Table IV contains the calibration levels of both methods. A volume of 1 ÎźL of the calibration standards was injected for all methods. Figure 2 shows the chromatogram of the 5 ppm calibration standard acquired in splitless mode.
70
Optimized GC-MS solution for semivolatiles (SVOC) analysis in environmental samples in compliance with the U.S. EPA Method 8270D
Sponsor Report
Table IV. DFTPP spectrum check for ion abundance criteria Calibration Standard
Splitless Conc. (ppm)
Split Conc. (ppm)
Cal 1 Cal 2 Cal 3 Cal 4 Cal 5 Cal 6 Cal 7 Cal 8 Cal 9
0.2 0.5 1.0 2.0 5.0 10.0 20.0 35.0 50.0
2.0 5.0 10.0 20.0 35.0 50.0 100.0 200.0 –
Figure 2. Total ion current (TIC) chromatogram of the 5 ppm EPA 8270 semivolatile calibration standard injected in splitless mode.
RESULTS AND DISCUSSION Splitless method 0.2–50 ppm calibration The average relative response factors of the 76 targeted compounds and six surrogates were calculated by analyzing the nine calibration standards from 0.2 ppm to 50 ppm in methylene chloride. Six compounds had Response Factors %RSD >20% and required an alternative curve fit. The %RSDs of those compounds calibrated using average response factors and r2 values for the six alternative fit compounds are shown in Table V. Split method 2–200 ppm calibration The average response factors of the 76 targeted compounds and six surrogates were calculated by analyzing eight calibration standards with concentrations ranging from 2 ppm to 200 ppm prepared in methylene chloride. Seven compounds had Response Factors %RSD >20% and required an alternate curve fit. The %RSDs of those compounds calibrated using average response factors and r2 values for the seven alternative fit compounds are shown in Table VI. Instant Connect Helium Saver module Method 8270D was also tested with the Instant Connect Helium Saver module (P/N 19070013). Depending on the experimental conditions, the Helium Saver module allows up to 14 years of GC and GC-MS operation from a single helium cylinder. The inlet is supplied with two different gases: nitrogen is used for the septum purge and split flows with only helium supplying the analytical column. Because of this innovative and patented solution, helium consumption is dramatically reduced. After time for equilibration, the GC-MS tuning mixture was injected and passed the criteria for EPA Method 8270D. Standards for a calibration curve (0.2–50 ppm and 2–200 ppm) were injected, and the data processed. Table VII(a) shows the results for splitless method and Table VII(b) reports split method. In both configurations (SSL and Helium Saver) and for both methods (split and splitless), less than 10% of compounds required an alternative curve fit. All the others had RSD% less than 20% with linear fit. 71
Law, R.; Cojocariu, C.; Cavagnino, D.
Sponsor Report Minimum response factors EPA Method 8270D requires a minimum relative response factor (RRF) for any point of the calibration curve for several compounds in the targeted list. Table VIII presents those minimum relative response factor requirements and the minimum RRF across all curves performed on the ISQ 7000 single quadrupole GC-MS system. Retention times The four methods: splitless, splitless with Helium Saver, split, and split with Helium Saver, were developed over a period of three weeks. Table IX demonstrates the stability of the retention times over this period of time. During this time, the liner and septa were changed and the analytical column trimmed. Still, the retention times are reproducible using different methods and different inlet modules. Table IX shows a comparison of the retention times obtained using different methods and inlet modules. NeverVent technology Specifically designed to simplify the routine maintenance procedures and to maximize the GC-MS instrument uptime, the proprietary Vacuum Probe Interlock (VPI) and the V-lock solution available on the ISQ 7000 single quadrupole GC-MS system allow ion source cleaning or column replacement to be performed quickly without breaking the MS vacuum, saving up to 98% of the time typically required to perform those operations. Thanks to the VPI, the ion source can be fully removed—including all of the lenses and the repeller—through the front vacuum interlock, without venting the system. This allows cleaning the source, swapping it, or changing ionization type, and being ready to run samples within minutes, not hours or days. Additionally, the V-lock technology allows the MS under vacuum to be fully isolated from the GC system, permitting not only a quick replacement of the analytical column when necessary, but also quick and safe performance of regular maintenance at the injector side, like replacing the septum or the liner or trimming the analytical column, without the use of any additional postcolumn or auxiliary gas flow into the MS.
72
Optimized GC-MS solution for semivolatiles (SVOC) analysis in environmental samples in compliance with the U.S. EPA Method 8270D
Sponsor Report
Table V. Response factors %RSDs as well as coefficient of determination values (r2) determined from the calibration curve acquired over a concentration range of 0.2–50 ppm (splitless injections). 2
Compound
%RSD
r
N-Nitrosodimethylamine
11.53
—
Pyridine
10.23
2-fluorophenol (surrogate) Phenol-d6 (surrogate)
Compound
2
%RSD
r
Acenaphthylene
8.24
—
—
1,2-Dinitrobenzene
14.85
—
5.57
—
3-Nitroaniline
8.09
—
4.99
—
Acenaphthene-d10
5.78
—
Aniline
6.39
—
Acenaphthene
7.57
—
Phenol
7.30
—
2,4-dinitrophenol
—
0.9867
Bis(2-chloroethyl) ether
7.95
—
Phenol, 4-nitro-
18.15
—
Phenol, 2-chloro-
6.19
—
Dibenzofuran
6.78
—
Benzene, 1,3-dichloro-
6.29
—
2,4-dinitrotoluene
12.32
—
1,4-Dichlorobenzene-d4
4.90
—
Phenol, 2,3,5,6-tetrachloro-
—
0.9957
Benzene, 1,4-dichloro-
7.57
—
Phenol, 2,3,4,6-tetrachloro-
—
0.9965
Benzyl alcohol
7.33
—
Diethyl Phthalate
5.60
—
Benzene, 1,2-dichloro-
7.43
—
4-chlorophenylphenylether
6.50
—
Phenol, 2-methyl-
6.27
—
Fluorene
7.31
—
Bis(2-chloroisopropyl) ether
6.31
—
4-nitroaniline
7.88
—
Phenol, 3&4-methyl-
6.52
—
4,6-Dinitro-2-methylphenol
—
0.9945
N-Nitroso-di-n-propylamine
6.63
—
Diphenylamine
9.61
—
Ethane, hexachloro-
5.80
—
Azobenzene
7.06
—
Nitrobenzene-D5 (surrogate)
5.90
—
2,4,6-tribromophenol (surrogate)
—
0.9963
Benzene, nitro-
3.20
—
4-bromophenylphenylether
4.30
—
Isophorone
3.90
—
Hexachlorobenzene
8.18
—
Phenol, 2-nitro-
13.14
—
Phenol, pentachloro-
—
0.9960
Phenol, 2,4-dimethyl-
4.52
—
Phenanthrene
10.88
—
Bis (2-chloroethoxy) methane
5.17
—
Phenanthrene-d10-
3.54
—
Phenol, 2,4-dichloro-
4.76
—
Anthracene
11.38
—
Benzene, 1,2,4-trichloro-
6.17
—
Carbazole
9.69
—
Naphthalene
8.26
—
Di-n-butyl phthalate
8.10
—
Naphthalene-d8
5.02
—
Fluoranthene
10.94
—
p-Chloroaniline
4.95
—
Pyrene
10.68
—
1,3-Butadiene, 1,1,2,3,4,4-hexachloro-
5.36
—
p-Terphenyl-d14 (surrogate)
6.76
—
Phenol, 4-chloro-3-methyl-
4.14
—
Benzyl butyl phthalate
8.69
—
Naphthalene, 2-methyl
7.54
—
Bis (2-ethylhexyl) adipate
6.08
—
Naphthalene, 1-methyl-
7.00
—
Benz[a]anthracene
9.68
—
Hexachlorocyclopentadiene
9.80
—
Chrysene
9.38
—
Phenol, 2,4,5-trichloro-
8.21
—
Chrysene-d12
4.02
—
Phenol, 2,4,6-trichloro-
5.90
—
Bis (2-ethylhexyl) phthalate
7.42
—
2-fluorobiphenyl (surrogate)
4.99
—
Di-n-octylphthalate
6.30
—
Naphthalene, 2-chloro-
7.24
—
Benzo[b]fluoranthene
6.70
—
2-Nitroaniline
10.43
—
Benzo[k]fluoranthene
8.48
—
1,4-Dinitrobenzene
16.05
—
Benzo[a]pyrene
6.11
—
Dimethyl phthalate
5.66
—
Perylene-d12
5.73
—
Benzene, 1,3-dinitro-
13.75
—
Indeno[1,2,3-cd]pyrene
6.36
—
2,6-dinitrotoluene
6.11
—
Dibenzo[a,h]anthracene
6.39
—
Benzo[g,h,i]perylene
7.75
—
Boldface indicates Internal Standards 73
Law, R.; Cojocariu, C.; Cavagnino, D.
Sponsor Report Table VI. Response factors %RSDs as well as coefficient of determination values (r2) determined from the calibration curve acquired over a concentration range of 0.2–200 ppm (10:1 split injections). Compound
r
N-Nitrosodimethylamine
6.31
—
Pyridine
10.80
2-fluorophenol (surrogate) Phenol-d6 (surrogate)
r
Acenaphthylene
6.59
—
—
1,2-Dinitrobenzene
15.11
—
4.30
—
3-Nitroaniline
14.42
4.19
—
Acenaphthene-d10
7.23
—
Aniline
4.89
—
Acenaphthene
7.98
—
Phenol
5.48
—
2,4-dinitrophenol
—
0.9984
Bis(2-chloroethyl) ether
4.45
—
Phenol, 4-nitro-
—
0.9982
Phenol, 2-chloro-
4.94
—
Dibenzofuran
8.91
—
Benzene, 1,3-dichloro-
5.03
—
2,4-dinitrotoluene
18.65
—
1,4-Dichlorobenzene-d4
6.01
—
Phenol, 2,3,5,6-tetrachloro-
17.58
—
Benzene, 1,4-dichloro-
5.09
—
Phenol, 2,3,4,6-tetrachloro-
12.33
—
Benzyl alcohol
9.21
—
Diethyl Phthalate
7.83
—
Benzene, 1,2-dichloro-
4.76
—
4-chlorophenylphenylether
7.93
—
Phenol, 2-methyl-
6.77
—
Fluorene
9.13
—
Bis(2-chloroisopropyl) ether
4.85
—
4-nitroaniline
13.30
—
Phenol, 3&4-methyl-
5.92
—
4,6-Dinitro-2-methylphenol
-
0.9983
N-Nitroso-di-n-propylamine
6.23
—
Diphenylamine
8.13
—
Ethane, hexachloro-
4.85
—
Azobenzene
9.24
—
Nitrobenzene-D5 (surrogate)
10.59
—
2,4,6-tribromophenol (surrogate)
13.23
—
Benzene, nitro-
10.24
—
4-bromophenylphenylether
6.37
—
Isophorone
5.18
—
Hexachlorobenzene
5.72
—
Phenol, 2-nitro-
19.20
—
Phenol, pentachloro-
—
0.9981
Phenol, 2,4-dimethyl-
4.92
—
Phenanthrene
6.32
—
Bis (2-chloroethoxy) methane
8.67
—
Phenanthrene-d10-
6.95
—
Phenol, 2,4-dichloro-
5.68
—
Anthracene
7.23
—
Benzene, 1,2,4-trichloro-
5.74
—
Carbazole
11.25
—
Naphthalene
5.74
—
Di-n-butyl phthalate
6.69
—
Naphthalene-d8
6.53
—
Fluoranthene
7.64
—
p-Chloroaniline
6.02
—
Pyrene
6.93
—
1,3-Butadiene, 1,1,2,3,4,4-hexachloro-
5.54
—
p-Terphenyl-d14 (surrogate)
6.38
—
Phenol, 4-chloro-3-methyl-
8.26
—
Benzyl butyl phthalate
6.97
—
Naphthalene, 2-methyl
6.97
—
Bis (2-ethylhexyl) adipate
6.16
—
Naphthalene, 1-methyl-
7.35
—
Benz[a]anthracene
7.43
—
6.17
—
—
Compound
2
%RSD
Hexachlorocyclopentadiene
0.9991 Chrysene
Phenol, 2,4,5-trichloro-
10.39
—
Chrysene-d12
10.49
—
Phenol, 2,4,6-trichloro-
7.92
—
Bis (2-ethylhexyl) phthalate
4.95
—
2-fluorobiphenyl (surrogate)
6.45
—
Di-n-octylphthalate
8.70
—
Naphthalene, 2-chloro-
8.16
—
Benzo[b]fluoranthene
7.06
—
2-Nitroaniline
17.03
—
Benzo[k]fluoranthene
6.26
—
6.81
—
Perylene-d12
14.99
—
0.9976 Indeno[1,2,3-cd]pyrene
1,4-Dinitrobenzene
—
Dimethyl phthalate
8.30
Benzene, 1,3-dinitro2,6-dinitrotoluene
74
2
%RSD
Boldface indicates Internal Standards
— 11.55
0.9980 Benzo[a]pyrene — —
6.15
—
Dibenzo[a,h]anthracene
6.91
—
Benzo[g,h,i]perylene
7.06
—
Optimized GC-MS solution for semivolatiles (SVOC) analysis in environmental samples in compliance with the U.S. EPA Method 8270D
Sponsor Report
Table VII(a). Response factors %RSDs for the 76 targeted compounds and internal standards, as well as r2, for alternative ďŹ t calibrations using the Instant Connect Helium Saver module in splitless mode. Compound
2
%RSD
r
N-Nitrosodimethylamine
6.62
â&#x20AC;&#x201D;
Pyridine
10.56
â&#x20AC;&#x201D;
2-fluorophenol (surrogate)
6.37
Phenol-d6 (surrogate)
4.82
Aniline Phenol
Compound
2
%RSD
r
Acenaphthylene
7.34
â&#x20AC;&#x201D;
1,2-Dinitrobenzene
16.57
â&#x20AC;&#x201D;
â&#x20AC;&#x201D;
3-Nitroaniline
19.06
â&#x20AC;&#x201D;
â&#x20AC;&#x201D;
Acenaphthene-d10
3.99
â&#x20AC;&#x201D;
13.52
â&#x20AC;&#x201D;
Acenaphthene
4.68
â&#x20AC;&#x201D;
5.41
â&#x20AC;&#x201D;
2,4-dinitrophenol
â&#x20AC;&#x201D;
0.9938
Bis(2-chloroethyl) ether
17.24
â&#x20AC;&#x201D;
Phenol, 4-nitro-
3KHQRO FKORUR
6.34
â&#x20AC;&#x201D;
Dibenzofuran
Benzene, 1,3-dichloro-
5.80
â&#x20AC;&#x201D;
2,4-dinitrotoluene
1,4-Dichlorobenzene-d4
2.53
â&#x20AC;&#x201D;
Benzene, 1,4-dichloro-
5.17
â&#x20AC;&#x201D;
%HQ]\O DOFRKRO
18.38
.%HQ]HQH GLFKORUR
5.36
Phenol, 2-methylBis(2-chloroisopropyl) ether
â&#x20AC;&#x201D;
0.9950
6.21
â&#x20AC;&#x201D;
â&#x20AC;&#x201D;
0.9942
Phenol, 2,3,5,6-tetrachloro-
â&#x20AC;&#x201D;
0.9962
Phenol, 2,3,4,6-tetrachloro-
14.62
â&#x20AC;&#x201D;
Diethyl Phthalate
5.69
â&#x20AC;&#x201D; â&#x20AC;&#x201D;
â&#x20AC;&#x201D;
4-chlorophenylphenylether
5.32
â&#x20AC;&#x201D;
6.17
â&#x20AC;&#x201D;
Fluorene
9.43
â&#x20AC;&#x201D;
4.53
â&#x20AC;&#x201D;
4-nitroaniline
19.69
â&#x20AC;&#x201D;
Phenol, 3&4-methyl-
7.17
â&#x20AC;&#x201D;
4,6-Dinitro-2-methylphenol
â&#x20AC;&#x201D;
0.9893
N-Nitroso-di-n-propylamine
7.58
â&#x20AC;&#x201D;
Diphenylamine
6.12
â&#x20AC;&#x201D;
Ethane, hexachloro-
6.39
â&#x20AC;&#x201D;
Azobenzene
6.01
â&#x20AC;&#x201D;
Nitrobenzene-D5 (surrogate)
8.67
â&#x20AC;&#x201D;
2,4,6-tribromophenol (surrogate)
16.16
â&#x20AC;&#x201D;
%HQ]HQH QLWUR
8.86
â&#x20AC;&#x201D;
4-bromophenylphenylether
8.54
â&#x20AC;&#x201D;
Isophorone
5.52
â&#x20AC;&#x201D;
Hexachlorobenzene
5.49
â&#x20AC;&#x201D;
Phenol, 2-nitro-
17.07
â&#x20AC;&#x201D;
Phenol, pentachloro-
â&#x20AC;&#x201D;
0.9971
Phenol, 2,4-dimethyl-
8.44
â&#x20AC;&#x201D;
Phenanthrene
7.12
â&#x20AC;&#x201D;
Bis (2-chloroethoxy) methane
8.87
â&#x20AC;&#x201D;
Phenanthrene-d10-
2.95
â&#x20AC;&#x201D;
Phenol, 2,4-dichloro-
8.56
â&#x20AC;&#x201D;
Anthracene
12.18
â&#x20AC;&#x201D;
Benzene, 1,2,4-trichloro-
5.36
â&#x20AC;&#x201D;
Carbazole
6.86
â&#x20AC;&#x201D;
Naphthalene
5.91
â&#x20AC;&#x201D;
Di-n-butyl phthalate
6.59
â&#x20AC;&#x201D;
Naphthalene-d8
2.41
â&#x20AC;&#x201D;
Fluoranthene
8.46
â&#x20AC;&#x201D;
p-Chloroaniline
5.82
â&#x20AC;&#x201D;
Pyrene
7.82
â&#x20AC;&#x201D;
1,3-Butadiene, 1,1,2,3,4,4-hexachloro-
4.82
â&#x20AC;&#x201D;
p-Terphenyl-d14 (surrogate)
7.49
3KHQRO FKORUR PHWK\O
8.96
â&#x20AC;&#x201D;
Benzyl butyl phthalate
5.81
â&#x20AC;&#x201D; â&#x20AC;&#x201D;
1DSKWKDOHQH PHWK\O
5.95
â&#x20AC;&#x201D;
Bis (2-ethylhexyl) adipate
9.11
â&#x20AC;&#x201D;
Naphthalene, 1-methyl-
6.54
â&#x20AC;&#x201D;
Benz[a]anthracene
5.79
â&#x20AC;&#x201D;
6.90
â&#x20AC;&#x201D;
Hexachlorocyclopentadiene
â&#x20AC;&#x201D;
0.9959 Chrysene
Phenol, 2,4,5-trichloro-
13.52
â&#x20AC;&#x201D;
Chrysene-d12
4.59
â&#x20AC;&#x201D;
Phenol, 2,4,6-trichloro-
9.81
â&#x20AC;&#x201D;
Bis (2-ethylhexyl) phthalate
7.06
â&#x20AC;&#x201D;
2-fluorobiphenyl (surrogate)
6.00
â&#x20AC;&#x201D;
Di-n-octylphthalate
7.84
â&#x20AC;&#x201D;
Naphthalene, 2-chloro-
5.66
â&#x20AC;&#x201D;
Benzo[b]fluoranthene
8.98
â&#x20AC;&#x201D;
2-Nitroaniline
17.31
â&#x20AC;&#x201D;
Benzo[k]fluoranthene
11.28
â&#x20AC;&#x201D;
7.47
â&#x20AC;&#x201D;
1,4-Dinitrobenzene
â&#x20AC;&#x201D;
0.9962 Benzo[a]pyrene
Dimethyl phthalate
5.88
â&#x20AC;&#x201D;
Perylene-d12
5.38
â&#x20AC;&#x201D;
Benzene, 1,3-dinitro-
17.90
â&#x20AC;&#x201D;
Indeno[1,2,3-cd]pyrene
8.02
â&#x20AC;&#x201D;
2,6-dinitrotoluene
11.80
â&#x20AC;&#x201D;
Dibenzo[a,h]anthracene
5.99
â&#x20AC;&#x201D;
Benzo[g,h,i]perylene
7.43
â&#x20AC;&#x201D;
Boldface indicates Internal Standards
75
Law, R.; Cojocariu, C.; Cavagnino, D.
Sponsor Report Table VII(b). Response factors %RSDs for the 76 targeted compounds and internal standards, 2
as well as r , for alternative fit calibrations using the Instant Connect Helium Saver module in split mode. Compound
r
N-Nitrosodimethylamine
6.62
—
Pyridine
13.09
2-fluorophenol (surrogate)
6.02
Phenol-d6 (surrogate) Aniline
Compound
2
%RSD
r
Acenaphthylene
7.25
—
—
1,2-Dinitrobenzene
17.76
—
—
3-Nitroaniline
18.05
—
5.71
—
Acenaphthene-d10
4.15
—
6.13
—
Acenaphthene
7.36
—
Phenol
6.52
—
2,4-dinitrophenol
—
0.9965
Bis(2-chloroethyl) ether
5.69
—
Phenol, 4-nitro-
—
0.9978
Phenol, 2-chloro-
7.17
—
Dibenzofuran
6.90
—
Benzene, 1,3-dichloro-
7.28
—
2,4-dinitrotoluene
18.32
—
1,4-Dichlorobenzene-d4
3.26
—
Phenol, 2,3,5,6-tetrachloro-
—
0.9957
Benzene, 1,4-dichloro-
8.13
—
Phenol, 2,3,4,6-tetrachloro-
17.05
—
Benzyl alcohol
14.15
—
Diethyl Phthalate
6.09
—
Benzene, 1,2-dichloro-
6.95
—
4-chlorophenylphenylether
8.11
—
Phenol, 2-methyl-
6.68
—
Fluorene
8.51
—
Bis (2-chloroisopropyl) ether
6.28
—
4-nitroaniline
19.17
—
Phenol, 3&4-methyl-
6.42
—
4,6-Dinitro-2-methylphenol
—
0.9987
N-Nitroso-di-n-propylamine
7.31
—
Diphenylamine
7.24
—
Ethane, hexachloro-
9.32
—
Azobenzene
7.28
—
Nitrobenzene-D5 (surrogate)
10.02
—
2,4,6-tribromophenol (surrogate)
14.93
—
Benzene, nitro-
11.59
—
4-bromophenylphenylether
7.06
—
Isophorone
6.70
—
Hexachlorobenzene
7.82
—
Phenol, 2-nitro-
14.78
—
Phenol, pentachloro-
—
0.9991
Phenol, 2,4-dimethyl-
5.90
—
Phenanthrene
8.55
—
Bis (2-chloroethoxy) methane
5.64
—
Phenanthrene-d10-
3.85
—
Phenol, 2,4-dichloro-
5.96
—
Anthracene
6.87
—
Benzene, 1,2,4-trichloro-
6.67
—
Carbazole
8.99
—
Naphthalene
4.81
—
Di-n-butyl phthalate
7.05
—
Naphthalene-d8
3.84
—
Fluoranthene
7.25
—
p-Chloroaniline
5.55
—
Pyrene
6.05
—
1,3-Butadiene, 1,1,2,3,4,4-hexachloro-
7.15
—
p-Terphenyl-d14 (surrogate)
6.25
—
Phenol, 4-chloro-3-methyl-
7.32
—
Benzyl butyl phthalate
5.92
—
Naphthalene, 2-methyl
5.92
—
Bis (2-ethylhexyl) adipate
6.32
—
Naphthalene, 1-methyl-
6.15
—
Benz[a]anthracene
7.37
—
Hexachlorocyclopentadiene
6.90
—
Phenol, 2,4,5-trichloro-
12.06
—
Chrysene-d12
4.81
—
Phenol, 2,4,6-trichloro-
12.35
—
Bis (2-ethylhexyl) phthalate
6.27
—
2-fluorobiphenyl (surrogate)
7.30
—
Di-n-octylphthalate
6.56
—
Naphthalene, 2-chloro-
7.68
—
Benzo[b]fluoranthene
6.55
—
2-Nitroaniline
17.72
—
Benzo[k]fluoranthene
9.18
—
1,4-Dinitrobenzene
19.53
—
Benzo[a]pyrene
7.40
—
Dimethyl phthalate
7.46
—
Perylene-d12
8.17
—
Benzene, 1,3-dinitro-
18.89
—
Indeno[1,2,3-cd]pyrene
8.23
—
2,6-dinitrotoluene
13.59
—
Dibenzo[a,h]anthracene
7.15
—
Benzo[g,h,i]perylene
6.50
—
Boldface indicates Internal Standards
76
2
%RSD
—
0.9985 Chrysene
Optimized GC-MS solution for semivolatiles (SVOC) analysis in environmental samples in compliance with the U.S. EPA Method 8270D
Sponsor Report Table VIII (Part 1). EPA Method 8270D minimum relative response factors and those produced by the ISQ 7000 single quadrupole system Thermo Minimum
Thermo Minimum
EPA 8270D Minimum Response
Splitless
Phenol
0.8
1.990
Splitless Helium Saver 2.895
2.603
Split Helium Saver 2.767
Bis(2-chloroethyl) ether
0.7
1.499
2.225
1.929
2.134
Phenol, 2-chloro-
0.8
1.516
1.884
1.882
1.869
Phenol, 2-methyl-
0.7
1.412
1.802
1.719
1.771
Phenol, 3&4-methyl-
0.6
1.495
1.933
1.767
1.897
N-Nitroso-di-n-propylamine
0.5
1.110
1.886
1.254
1.579
Ethane, hexachloro-
0.3
0.530
0.439
0.716
0.690
Benzene, nitro-
0.2
0.316
0.469
0.404
0.471
Isophorone
0.4
0.708
0.989
0.869
0.995
Phenol, 2-nitro-
0.1
0.160
0.170
0.152
0.157
Phenol, 2,4-dimethyl-
0.2
0.389
0.453
0.430
0.465
Bis(2-chloroethoxy)methane
0.3
0.432
0.589
0.530
0.586
Phenol, 2,4-dichloro-
0.2
0.282
0.269
0.313
0.288
Naphthalene
0.7
1.085
1.247
1.176
1.260
p-Chloroaniline
0.01
0.464
0.493
0.497
0.546
1,3-Butadiene, 1,1,2,3,4,4-hexachloro-
0.01
0.112
0.118
0.175
0.116
Phenol, 4-chloro-3-methyl-
0.2
0.342
0.394
0.382
0.418
Naphthalene, 2-methyl
0.4
0.785
0.730
0.726
0.724
Hexachlorocyclopentadiene
0.05
0.236
0.128
0.213
0.044
Phenol, 2,4,6-trichloro-
0.2
0.345
0.322
0.372
0.298
Phenol, 2,4,5-trichloro-
0.2
0.324
0.286
0.368
0.300
Naphthalene, 2-chloro
0.8
1.232
1.388
1.314
1.349
2-Nitroaniline
0.01
0.335
0.406
0.339
0.455
Dimethyl phthalate
0.01
1.361
1.511
1.442
1.482
2,6-dinitrotoluene
0.2
0.229
0.259
0.258
0.242
Acenaphthylene
0.9
1.899
2.216
2.063
2.165
3-Nitroaniline
0.01
0.298
0.336
0.428
0.541
2,4-dinitrophenol
0.01
0.055
0.042
0.045
0.025
Acenaphthene
0.9
1.312
1.574
1.383
1.417
2,4-dinitrotoluene
0.2
0.304
0.327
0.316
0.330
Dibenzofuran
0.8
1.840
1.907
1.811
1.863
Phenol, 4-nitro-
0.01
0.167
0.042
0.124
0.055
Diethyl Phthalate
0.01
1.335
1.676
1.508
1.518
4-chlorophenylphenylether
0.4
0.740
0.609
0.692
0.621
4-nitroaniline
0.01
0.306
0.360
0.315
0.296
Fluorene
0.9
1.434
1.647
1.471
1.470
4,6-Dinitro-2-methylphenol
0.01
0.079
0.057
0.063
0.047
Diphenylamine
0.01
0.683
0.897
0.750
0.799
4-bromophenylphenylether
0.1
0.477
0.332
0.241
0.206
Hexachlorobenzene
0.1
0.324
0.256
0.283
0.267
Phenol, pentachloro-
0.05
0.131
0.077
0.064
0.049
Phenanthrene
0.7
1.125
1.335
1.289
1.275
Anthracene
0.7
1.270
1.138
1.272
1.347
Carbazole
0.01
1.070
1.407
1.006
1.156
Di-n-butyl phthalate
0.01
1.314
1.856
1.517
1.626
Compound
Split (10:1)
77
Law, R.; Cojocariu, C.; Cavagnino, D.
Sponsor Report Table VIII (Part 2). EPA Method 8270D minimum relative response factors and those produced by the ISQ 7000 single quadrupole system Thermo Minimum
Thermo Minimum
EPA 8270D Minimum Response
Splitless
0.6
1.263
Splitless Helium Saver 1.123
Pyrene
0.6
1.072
Benzyl butyl phthalate
0.01
0.496
Bis(2-ethylhexyl)phthalate
0.01
Chrysene Benz[a]anthracene
1.268
Split Helium Saver 1.234
1.326
1.296
1.487
0.906
0.677
0.847
0.741
1.225
0.941
1.144
0.7
1.025
1.110
1.164
1.102
0.8
1.068
1.228
1.171
1.124
Di-n-octylphthalate
0.01
1.465
2.673
2.084
2.413
Benzo[b]fluoranthene
0.7
1.364
1.417
1.592
1.432
Benzo[k]fluoranthene
0.7
1.292
1.185
1.586
1.396
Benzo[a]pyrene
0.7
1.353
1.420
1.500
1.414
Indeno[1,2,3-cd]pyrene
0.5
1.600
1.794
1.727
1.866
Dibenzo[a,h]anthracene
0.4
1.393
1.645
1.472
1.617
Benzo[g,h,i]perylene
0.5
1.302
1.560
1.406
1.636
Compound
Fluoranthene
Split (10:1)
Table IX (Part 1). Retention times (RT) for the four methods
3.71
Split (10:1) Helium Saver RT (min) 3.66
Splitless Helium Saver RT (min) 3.29
3.74
3.68
3.33
5.08
5.07
5.04
4.98
Phenol-d6 (surrogate)
5.96
5.93
5.91
5.92
Phenol
5.97
5.94
5.93
5.92
Aniline
5.98
5.95
5.94
5.92
Bis(2-chloroethyl) ether
6.04
6.00
5.98
5.97
Phenol, 2-chloro-
6.08
6.05
6.03
6.02
Benzene, 1,3-dichloro-
6.20
6.17
6.15
6.14
1,4-Dichlorobenzene-d4
6.23
6.20
6.18
6.17
Benzene, 1,4-dichloro-
6.25
6.21
6.20
6.19
Benzyl alcohol
6.39
6.36
6.34
6.34
Benzene, 1,2-dichloro-
6.42
6.38
6.37
6.36
Phenol, 2-methyl-
6.49
6.46
6.45
6.46
Bis(2-chloroisopropyl)ether
6.51
6.48
6.47
6.46
Phenol, 3&4-methyl-
6.63
6.60
6.59
6.59
N-Nitroso-di-n-propylamine
6.67
6.62
6.60
6.61
Ethane, hexachloro-
6.68
6.65
6.64
6.63
Nitrobenzene-D5 (surrogate)
6.77
6.73
6.72
6.72
Benzene, nitro-
6.79
6.75
6.74
6.74
Isophorone
7.00
6.96
6.94
6.95
Phenol, 2-nitro-
7.06
7.03
7.02
7.02
Phenol, 2,4-dimethyl-
7.09
7.06
7.05
7.06
Bis(2-chloroethoxy)methane
7.18
7.14
7.13
7.13
Phenol, 2,4-dichloro-
7.27
7.23
7.22
7.23
Benzene, 1,2,4-trichloro-
7.33
7.30
7.29
7.29
Naphthalene-d8
7.37
7.34
7.33
7.33
Splitless RT (min)
Split (10:1) RT (min)
Pyridine
3.66
N-Nitrosodimethylamine
3.71
2-fluorophenol (surrogate)
Compound
78
Optimized GC-MS solution for semivolatiles (SVOC) analysis in environmental samples in compliance with the U.S. EPA Method 8270D
Sponsor Report
Table IX (Part 2). Retention times (RT) for the four methods
7.36
Split (10:1) Helium Saver RT (min) 7.35
Splitless Helium Saver RT (min) 7.35
7.46
7.43
7.42
7.42
7.53
7.50
7.49
7.49
Phenol, 4-chloro-3-methyl-
7.87
7.84
7.83
7.84
Naphthalene, 2-methyl
7.99
7.95
7.94
7.95
Naphthalene, 1-methyl-
8.08
8.04
8.03
8.04
Hexachlorocyclopentadiene
8.17
8.13
8.12
8.13
Phenol, 2,4,6-trichloro-
8.25
8.21
8.21
8.22
Phenol, 2,4,5-trichloro-
8.28
8.25
8.24
8.25
2-fluorobiphenyl (surrogate)
8.31
8.27
8.26
8.27
Naphthalene, 2-chloro-
8.41
8.37
8.36
8.37
2-Nitroaniline
8.53
8.49
8.49
8.50
1,4-Dinitrobenzene
8.63
8.59
8.58
8.60
Dimethyl phthalate
8.70
8.66
8.64
8.66
Benzene, 1,3-dinitro-
8.74
8.69
8.68
8.70
2,6-dinitrotoluene
8.77
8.72
8.71
8.73
Acenaphthylene
8.77
8.73
8.72
8.73
Compound
Splitless RT (min)
Split (10:1) RT (min)
Naphthalene
7.39
p-Chloroaniline 1,3-Butadiene, 1,1,2,3,4,4-hexachloro-
CONCLUSION The Thermo Scientific ISQ 7000 single quadrupole GC-MS system with the ExtractaBrite ion source and the innovative NeverVent technology is the perfect solution to perform the EPA 8270D Method. Thanks to the extended dynamic range detection system, the ISQ 7000 GC-MS system allows covering a 0.2–200 ppm range with the same column and liner. Seventy-six compounds were reported, and each fulfilled the EPA 8270D requirements in terms of minimum response factors and linearity. Chromeleon CDS software, with the Environmental Reporting package, offers unparallel flexibility, scalability, and compliance. It provides compliance with EPA 8270D Method requirements offering a full complement of standard reports including DFTPP Tune Check report, Breakdown report, Internal Standard Summary report, Tentatively Identified Compounds report, various quality control reports for check standards, laboratory control samples, matrix spikes, surrogate recoveries, and more. The Thermo Scientific Instant Connect Helium Saver Module is a unique tool that can be used to reduce the cost per analysis, without compromising the analytical results. The Helium Saver Module makes laboratories more efficient and environmentally friendly, saving 90% of helium during each run. The ExtractaBrite ion source design, as integrated in the ISQ 7000 GC-MS system, keeps the system cleaner, longer. With heat throughout the ion optics and the patented RF lens, the ISQ 7000 GC-MS system has been proven to be capable to analyze more dirty samples per day, with maximum uptime. Even better, when the instrument finally requires cleaning, the column needs to be replaced or trimmed, or maintenance is required at the injector side, the NeverVent technology offers the user the possibility to operate without venting the MS system, in a very fast and simple way.
79
Sponsor Report
Law, R.; Cojocariu, C.; Cavagnino, D.
REFERENCES
1. United States Environmental Protection Agency (U.S. EPA). Method 8270D (SW- 846): Semivolatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS), Revision 5, July 2014. https://www.epa.gov/sites/production/files/2015-12/documents/8270d.pdf [Accessed February 11th, 2018]. 2. Eichelberger, J. W.; Harris, L. E.; Budde, W. L. Anal. Chem., 1975, 47 (7), pp 995–1000. 3. Donnelly, J. R. J. Assoc. Off. Anal. Chem., 1988, 71 (2), pp 434–439. 4. Tondeur, Y.; Niederhutl, W. J.; Campana, J. E.; Mitchum, R. K.; G. Sovocool, W.; Donnelly, J. R. Biological Mass Spectrometry, 1988, 15 (8), pp 429–439. This sponsor report is the responsibility of Thermo Fisher Scientific.
80
VIDEO WEBSITE
Releases
DMA-80 - The most successful Hg analyzer in the market The Milestone DMA-80 is a direct mercury analyzer of solid, liquid, and gas samples. Analysis time is 5 minutes only and no sample preparation is required. The DMA-80 is based on the principles of sample thermal decomposition, mercury amalgamation and atomic absorption detection. With over 1300 units installed in 80 different Countries worldwide, the DMA-80 is the most successful direct mercury analyzer in the market.
8 good reasons to choose the Milestone DMA-80 No sample preparation - The DMA-80 does not require any sample preparation or other wet chemistry prior the analysis. This means ease of use, low running cost and no need for hazardous chemicals to purchase, handle and dispose. Best analytical performance - Combining an innovative mercury measuring system with a unique optical path spectrophotometer, the DMA-80 achieves a detection limit as low as 0.001 nanograms of mercury and is capable of measuring up to 30,000 nanograms of mercury, equivalent to a concentration of 300 mg/kg (300 ppm) on a 100 mg sample analysis. Ease of use - Just weigh your sample, load it onto the built-in auto-sampler and press 'start'. The DMA80 is so simple to use that it can be operated in the field, not only in the analytical laboratory. High productivity - The DMA-80 is incredibly fast. A complete analysis -start to finish, takes 5 minutes. Sample weight is automatically transferred from the analytical balance. The dual-tray auto-sampler allows sample loading 'on-the-fly', for a continuous operation of the instrument. Lowest cost of analysis - Ease of use, speed of analysis, catalyst and amalgamator long lifetime, sample boats durability and the possibility of using air as combustion and carrier gas minimize the DMA80 cost of analysis. Easy maintenance - All the DMA-80 components, such as the catalytic furnace, amalgamator and spectrophotometer, are easily accessible for routine cleaning and maintenance. Largest installed base - With over 1300 units installed in 80 different Countries worldwide, Milestone is the acknowledged market leader in direct mercury determination. Our extensive experience enables us to provide the highest level of application and service support. Official methods compliance - The DMA-80 has been used to develop the US EPA method 7473 (Mercury in solids and solutions by thermal decomposition, amalgamation, and atomic absorption spectrophotometry). It is furthermore compliant with ASTM method D-6722-01 (Total mercury in coal and coal combustion residues) and ASTM method D-7623- 10 (Total mercury in crude oil).
82
SelectScienceÂŽ is the leading independent online publisher connecting scientists to the best laboratory products and applications. Access 2 Million+ Decision Makers
Working with Scientists to Make the FutWorking with Scientists to Make the Future Healthier. Informing scientists about the best products and applications. Connecting manufacturers with their customers to develop, promote and sell technologies.ure Healthier.
VIDEO
WEBSITE
Releases
BrJAC is starting a partnership with SelectScience
®
With the purpose of providing BrJAC readers an electronic communication channel of reputation widely recognized as reliable, up-to-date and comprehensive, BrJAC and SelectScience® are starting a partnership series of guest editorial articles. SelectScience® pioneers online communication and promotes scientific success since 1998 Working with Scientists to Make the Future Healthier SelectScience® promotes scientists and their work, accelerating the communication of successful science. SelectScience® informs scientists about the best products and applications through online peerto-peer information and product reviews. Scientists can make better decisions using independent, expert information and gain easy access to manufacturers. SelectScience® informs the global community through Editorial, Q&A and Application Articles, Featured Topics, Event Coverage, Video and Webinar programs. Some recent contributions from SelecScience® to the scientific community Webinar: Long-Chain Petroleum Hydrocarbons Typing, Sample Prep and Analysis of VOCs in Soil by GC-MS – The analysis of organic contaminants in soil using EPA regulated methods is discussed. The routine testing solution that improved productivity and reliability of an environmental laboratory is presented. Part I: Analysis of Long-Chain Petroleum Hydrocarbons and VOCs in Soil by GC-MS Part II: Instrument Demands on Routine Lab Analysis of VOCs in Soil Using EPA Regulated Methods Access this webinar here Editorial Article: Meeting the Growing Challenges of Pesticides and Contaminants – Special Feature. From field to food discover the technology scientists are using to monitor food and environmental samples in this special feature. The impact pesticides and other contaminants have on our environment and food, and how this is driving the development of new sensitive and accurate technologies are discussed. In this feature you can discover methods for detecting these contaminants in a range of matrices and useful resources from across the industry to help your lab workflow. Access this feature here Working with Manufacturers SelectScience® informs scientists about the best products and applications. Connects manufacturers with their customers to develop, promote and sell technologies. SelectScience® is a game-changer, empowering scientific customers to share success, peer-to-peer, through digital channels. Effective, independent placement and promotion increases brand awareness, product demand, sales success and customer feedback. Access to the Google-approved Reviews Program generates more customer ratings. Personalized Content Marketing Programs deliver measured marketing results and direct e-commerce referrals.
84
VIDEO
WEBSITE
Releases
Redefining ICP-MS triple quadrupole technology with unique ease of use Empowering you with technology to achieve more today and be ready to master future challenges tomorrow, the Thermo Scientific iCAP TQ ICP-MS helps futureproof your laboratory against evolving legislation requirements, enables you to explore developing markets, and pushes the boundaries of your research. Harness the power of Triple Quadrupole (TQ) ICP-MS with incredible accuracy and detection limits for the most challenging applications. Improved interference removal allows laboratories to tackle complex samples with ease and deliver data with the confidence of 'right first time' results.
Ease of use is the core concept behind the Thermo Scientific™ iCAP™ TQ ICP-MS, which has been designed for laboratories working in both routine and research applications. The system is based on a platform with an intuitive hardware design that simplifies the user experience. The operator-focused software streamlines workflows and integrates control of peripherals to automate sample handling. Key features of the iCAP TQ ICP-MS Unique ease-of-use Combining user-inspired hardware with intelligent software, the iCAP TQ ICP-MS and the iCAP TQs ICP-MS both enable laboratories to effortlessly develop and maintain methods that ensure confidence in data quality. Reaction Finder, which is the systems' unique method development assistant, enables you to tackle challenging matrices without wasting time on complex method development. Right-first-time results Employ the power of triple quadrupole technology for uncomplicated analyses with superior accuracy during both research and routine applications. Thanks to the advanced interference removal capabilities of the iCAP TQ ICP-MS, analysis of samples with complex matrices can be performed with superior limits of detection for more accurate data. Boundless capabilities Fully integrated plugins for Thermo Scientific Qtegra Intelligent Scientific Data Solution (ISDS) Software enable the easy implementation of advanced applications, including automated sample handling, autodilution, speciation, nanoparticle analysis and laser ablation. Qtegra Intelligent Scientific Data Solution Software Intuitive workflows and intelligent features offered with Qtegra Intelligent Scientific Data Solution (ISDS) Software simplify method development, increase throughput and minimize re-runs.
86
VIDEO
WEBSITE
Releases
Unstoppable GC-MS Routine Analysis Designed to satisfy routine laboratories evolving analytical needs, the Thermo Scientific™ ISQ™ 7000 Single Quadrupole GC-MS system offers extended uptime and robustness to maximize sample throughput, along with routine easy-to-use smart tools to simplify operation and speed up instrument familiarization. Featuring a range of configurations at different level of performances, the ISQ 7000 GC-MS is a flexible fit-for-purpose platform, fully upgradable from base to advanced highly sensitive configuration to boost performance when needed and ready-to-fit with continuous changing in regulations.
Laboratories performing food, environmental, or forensic toxicology testing demand analytical systems that are unstoppable in every way. That's the inspiration behind the ISQ 7000 GC-MS system. UNSTOPPABLE Sensitivity The ISQ 7000 GC-MS system delivers femtogram-level sensitivity, so you consistently meet required detection limits as you run samples, whether you run in SIM mode or in Full Scan. Achieving low detection limits requires breaking noise-reduction boundaries. The ISQ 7000 GC-MS system does so with a unique ion path that neutrals cannot navigate. Choose either the rugged Thermo Scientific ExtractaBrite ion source technology or the ultra-sensitive, ultra-robust Thermo Scientific Advanced Electron Ionization (AEI) source. UNSTOPPABLE Uptime Extended instrument uptime reduces turnaround time and overhead. Robust design ensures that your ISQ 7000 GC-MS system continues to produce the highest-quality results possible. Whether you select the ExtractaBrite or AEI ion source, you benefit from high matrix tolerance to minimize routine maintenance. With NeverVent technology for the ExtractaBrite source, it's possible to isolate the mass spectrometer from the gas chromatograph, allowing source cleaning, column replacement or injector maintenance, without downtime for venting. This boosts instrument productivity to unprecedented levels, meaning your time can be spent on producing quality results. UNSTOPPABLE Ease of Use The ISQ 7000 GC-MS system advances the user experience and learning with automated software for instrument tuning, method development, targeted quantification and untargeted screening workflows. The software also makes it easy to transition to the ISQ 7000 GC-MS system from other platforms. AutoSIM and t-SIM automate method development and optimization for targeted selected-ionmonitoring (SIM) workflows. Retention Time Alignment (RTA) adds an easy way to maintain retention times for high-throughput work. Untargeted screening methods are likewise simplified. Mass spectral deconvolution unravels heavy co-elution by reconstructing clean mass spectra, ready for library searching, identification, and confirmation. For any workflow, SmartTune simplifies tuning procedure and, if required, notifies the user for any necessary corrective actions.
88
Releases
CHROMacademy helps increase your knowledge, efficiency and productivity in the lab
CHROMacademy is the world's largest eLearning website for analytical scientists. With a vast library of high-quality animated and interactive eLearning topics, webcasts, tutorials, practical information and troubleshooting tools CHROMacademy helps you refresh your chromatography skills or learn something completely new. A subscription to CHROMacademy provides you with complete access to all content including: · Thousands of eLearning topics covering HPLC / GC / Sample Prep / Mass Spec / Infrared / Basic Lab Skills / Biochromatography Each channel contains e-Learning modules, webcasts, tutorials, tech tips, quick guides and interactive tools and certified assessments. With over 3,000 pages of content, CHROMacademy has something for everyone. · Video Training Courses Each course contains 4 x 1.5-hour video training sessions, released over 4 weeks, with full tutor support and certification. · Ask the Expert – 24-hour Chromatography Support A team of analytical experts are on hand to help fix your instrument and chromatographic problems, offer advice on method development & validation, column choice, data analysis and much more. · Assessments Test your knowledge, certificates awarded upon completion. · Full archive of Essential Guide Webcasts and Tutorials Over 70 training topics covered by industry experts. · Application Notes and LCGC Articles The latest application notes & LCGC articles. · Troubleshooting and Virtual Lab Tools Become the lab expert with our HPLC and GC Troubleshooters. · User Forum Communicate with others interested in analytical science.
Lite members have access to less than 5% of CHROMacademy content. Premier members get so much more! For more information, please visit www.chromacademy.com/subscription.html
90
Notices of Books Analytical Chemistry Applied to Emerging Pollutants Silvio Vaz Jr, Author 2018, Springer International Publishing This book discusses the main tools available for the emerging pollutants analysis. It also describes the representative environmental matrices (air, soil and water) and appropriate analytical methods for each matrix. Furthermore, it examines aspects of toxicology, chemometrics, sample preparation and green analytical chemistry; provides a broad overview of the potential analytical approaches for monitoring and controlling emerging pollutants. It is a valuable resource for all professionals concerned with emerging pollutant control in realworld situations. Read more…
Amostragem Fora e Dentro do Laboratório (Second Edition) Flávio Leite, Author March 2018, Átomo Sampling is a complex and very little explored science. This book covers the following topics: The sampler and the analyst; How much to sample; Sampling and inspection; Examples of sampling in different areas; Applying probability; The product to be analyzed; What to analyze, techniques and technologies involved; Sampling in the gas state; Sample uniformity; Ways and frequency of sampling; Sample identification; Sample preservation; Materials and cleaning; Sampling validation; Flow measurements in sampling. Read more…
Sampling and Analysis of Environmental Chemical Pollutants - A Complete Guide (Second Edition) Emma Popek, Author December 2017, Elsevier This book promotes the knowledge of data collection fundamentals and offers technically solid procedures and basic techniques that can be applied to daily workflow solutions. The book's organization emphasizes the practical issues facing the project scientist. This Guide is a resource that will help students and practicing professionals alike better understand the issues of environmental data collection. Read more…
Environmental Chemistry: An Analytical Approach Kenneth S. Overway, Author March 2017, Wiley This book covers the essentials of environmental chemistry and focuses on measurements that can be made in a typical undergraduate laboratory. Provides a review of general chemistry nestled in the story of the Big Bang and the formation of the Earth. Includes a primer on measurement statistics and quantitative methods to equip students to make measurements in lab. Encapsulates environmental chemistry in three chapters on the atmosphere, lithosphere and hydrosphere. Describes many instruments and methods used to make common environmental measurements. Read more…
91
Periodicals & Websites American Laboratory ® The American Laboratory publication is a platform that provides comprehensive technology coverage for laboratory professionals at all stages of their careers. Unlike single-channel publications, American Laboratory® is a multidisciplinary resource that engages scientists through print, digital, mobile, multimedia, and social channels to provide practical information and solutions for cutting-edge results. Addressing basic research, clinical diagnostics, drug discovery, environmental, food and beverage, forensics, and other markets, American Laboratory combines in-depth articles, news, and video to deliver the latest advances in their fields. Read more LCGC Chromatographyonline.com is the premier global resource for unbiased, peerreviewed technical information on the field of chromatography and the separation sciences. Combining all of the resources from the regional editions (LCGC North America, LCGC Europe, and LCGC Asia-Pacific) of award winning magazines, Chromatographyonline delivers practical, nuts-and-bolts information to help scientists and lab managers become more proficient in the use of chromatographic techniques and instrumentation, thereby making laboratories more productive and businesses around the world more successful. Read more… Scientia Chromatographica Scientia Chromatographica is the first and to date the only Latin American scientific journal dedicated exclusively to Chromatographic and Related Techniques (Mass Spectrometry, Sample Preparation, Electrophoresis, etc.). With a highly qualified and internationally recognized Editorial Board, it covers all chromatography topics (HPLC, GC, SFC) in all their formats, in addition to discussing many related topics such as "The Pillars of Chromatography", Quality Management, Troubleshooting, Hyphenation (GC-MS, LC-MS, SPE-LC-MS/MS) and others. It also provides columns containing general information for the area, such as: calendar, meeting report, bookstore, etc. Read more… Select Science SelectScience® promotes scientists and their work, accelerating the communication of successful science. SelectScience® informs scientists about the best products and applications through online peer-to-peer information and product reviews. Scientists can make better decisions using independent, expert information and gain easy access to manufacturers. SelectScience® informs the global community through Editorial Features, Event Coverage, Video and Webinar programs. Read more… Spectroscopy Spectroscopy's mission is to enhance productivity, efficiency, and the overall value of spectroscopic instruments and methods as a practical analytical technology across a variety of fields. Scientists, technicians, and laboratory managers gain proficiency and competitive advantage for the real-world issues they face through unbiased, peer-reviewed technical articles, trusted troubleshooting advice, and best-practice application solutions. Read more… 92
Events May 13 - 18 42nd International Symposium on Capillary Chromatography (ISCC) & 15th GCxGC Symposium Congress Centre, Riva del Garda, Italy www.iscc42.chromaleont.it/ May 21 - 24 41th Annual Meeting of the Brazilian Chemical Society (41th RASBQ) Rafain Palace Hotel, Foz do Iguaçu, PR, Brazil www.sbq.org.br/41ra/
June 3 - 6 2nd Latin American Congress of Clinical and Laboratory Toxicology (II TOXILATIN) Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil toxilatin2018.com/
June 19 - 22 40th International Conference on Environmental & Food Monitoring Santiago de Compostela, Spain www.iseac40.es
June 25 - 29 17th Conference on Chemometrics in Analytical Chemistry (CAC 2018) Halifax, Canada www.cac2018halifax.com
July 24 - 27 XII Workshop on Sample Preparation (XII WPA) Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil www3.iq.usp.br/ September 10 - 12 3rd International Plant Proteomics Organization World Congress (3rd INPPO) Padova, Italy inppo2018.dafnae.unipd.it September 12 - 14 10th European Conference on Pesticides and Related Organic Micropollutants in the Environment & 16th Symposium on Chemistry and Fate of Modern Pesticides Joined to 10th MGPR International Symposium of Pesticides in Food and the Environment in Mediterranean Countries Bologna, Italy www.iaeac.com/
93
Events September 16 - 19 th th 19 Brazilian Meeting on Analytical Chemistry (19 ENQA) 7th Ibero-American Congress of Analytical Chemistry (7th CIAQA) Complexo Acqua DiRoma, Caldas Novas, GO, Brazil enqa2018.com.br/ September 19-20 19th World Congress on Analytical & Bioanalytical Techniques Singapore analytika.pharmaceuticalconferences.com November 4 - 8 6th Brazilian Meeting on Forensic Chemistry (6th ENQFor) & 3rd Meeting of the Brazilian Society of Forensic Sciences (SBCF) Convention Center of RibeirĂŁo Preto, SP, Brazil www.sbcf.org.br November 12 - 15 XIII Latin American Symposium on Environmental Analytical Chemistry (XIII LASEAC) La Serena, Chile www.eventotal.cl/ December 8 - 12 7th Brazilian Conference on Mass Spectrometry (7th BrMASS) Windsor Barra Hotel, Rio de Janeiro, RJ, Brazil http://www.brmass.com
94
Author's Guidelines The Brazilian Journal of Analytical Chemistry (BrJAC) is a peer-reviewed scientific journal intended for professionals and institutions acting mainly in all branches of Analytical Chemistry. BrJAC is an open access journal which does not charge authors an article processing fee. Scope BrJAC is dedicated to professionals involved in science, technology and innovation projects in the area of analytical chemistry at universities, research centers and in industry. About this journal BrJAC publishes original, unpublished scientific articles and technical notes that are peer reviewed in the double-blind way. In addition, it publishes reviews, interviews, points of view, letters, sponsor reports, and features related to analytical chemistry. BrJAC's review process begins with an initial screening of the manuscripts by the editor-in-chief, who evaluates the adequacy of the study to the journal scope. Manuscripts accepted in this screening are then forwarded to at least two referees indicated by the editors. As evaluation criteria, the referees will employ originality, scientific quality and contribution to knowledge in the field of Analytical Chemistry, the theoretical foundation and bibliography, the presentation of relevant and consistent results, compliance to the journal's guidelines, and the clarity of writing and presentation. Brief description of the BrJAC sections · Articles: Full descriptions of an original research finding in Analytical Chemistry. Manuscripts submitted for publication as articles, either from universities, research centers, industry or any other public or private institution, cannot have been previously published or be currently submitted for publication in another journal. Articles undergo double-blind full peer review. · Reviews: Articles on well-established subjects, including a critical analysis of the bibliographic references and conclusions. Manuscripts submitted for publication as reviews must be original and unpublished, and undergo double-blind full peer review. · Technical Notes: Concise descriptions of a development in analytical method, new technique, procedure or equipment falling within the scope of BrJAC. Technical notes also undergo double-blind full peer review. The title of the manuscript submitted for technical note must be preceded by the words "Technical note". · Sponsor Reports: Concise descriptions of technical studies not submitted for review by referees. Sponsor responsibility documents. · Letters: Discussions, comments, suggestions on issues related to Analytical Chemistry, and consultations to authors. Letters are welcome and will be published at the discretion of the editor-in-chief. · Points of view: The expression of a personal opinion on some relevant subject in Analytical Chemistry. · Interviews: Renowned chemist researchers are invited to talk with BrJAC about their expertise and experience in Analytical Chemistry. · Releases: Articles providing new and relevant information for the community involved in analytical chemistry, and companies' announcements on the launch of new products of interest in analytical chemistry. · Features: A feature article gives to the reader a more in-depth view of a topic, a person or opinion of acknowledged interest for Analytical Chemistry. Manuscript preparation (download a template on the BrJAC website) The manuscript submitted to BrJAC must be written in English and should be as clear and succinct as possible. It must include a title, an abstract, a graphical abstract, keywords, and the following sections: Introduction, Methods, Results and Discussion, Conclusion, and References. Because the manuscripts are subjected to double-blind review, they must NOT contain the authors' names, affiliations, or acknowledgments. The manuscript must be typed in Arial font size 11 pt., and the lines numbered consecutively and double-spaced throughout the text, except in the figure captions, titles of tables and references. 95
Author's Guidelines The manuscript title should be short, clear and succinct, and a subtitle may be used, if needed. The abstract should include the objective of the study, essential information about the methods, the main results and conclusions. Then, three to five keywords must be indicated. The section titles should be typed in bold and subsections in italics. Graphics and tables must be numbered according to their citation in the text, and should appear close to the discussion about them. For figures use Arabic numbers, and for tables use Roman numbers. The captions for the figures must appear below the graphic; for the tables, above. The same result should not be presented by more than one illustration. For figures, graphs, diagrams, tables, etc. identical to others previously published in the literature, the author must ask for permission for publication from the company or scientific society holding the copyrights, and send this permission to the BrJAC editor-in-chief with the final version of the manuscript. The chemical nomenclature should conform to the rules of the International Union of Pure and Applied Chemistry (IUPAC) and Chemical Abstracts Service. It is recommended that, whenever possible, authors follow the International System of Units, the International Vocabulary of Metrology (VIM) and the NIST General Table of Units of Measurement. Abbreviations are not recommended except those recognized by the International Bureau of Weights and Measures or those recorded and established in scientific publications. If the abbreviations are numerous and relevant, place their definitions in a separate section (Glossary). The manuscript must include only the consulted references, numbered according to their citation in the text, with numbers in square brackets. It is not recommended to mention several references with identical statements - select the author who demonstrated them. It is recommended that references older than 5 (five) years be avoided, except in relevant cases. Include references that are accessible to readers. References should be thoroughly checked for errors before submission. Manuscripts must be submitted in conjunction with an analysis report of plagiarism obtained through anti-plagiarism software. BrJAC indicates CopySpider© 2013 freeware to support plagiarism checking analyzes. Download the CopySpider freeware: www.copyspider.com.br
Examples of reference formatting Journals 1. Arthur, K. L.; Turner, M. A.; Brailsford, A. D.; Kicman, A. T.; David A. Cowan, D. A.; Reynolds, J. C.; Creaser, C. S. Anal. Chem. 2017, 89, pp 7431- 7437 (DOI: 10.1021/acs.analchem.7b000940). The titles of journals must be abbreviated as defined by the Chemical Abstracts Service Source Index (http://cassi.cas.org/search.jsp). If a paper does not have a full reference, please provide its DOI, if available, or its Chemical Abstracts reference information. Electronic journals 2. Natarajan, S.; Kempegowda, B. K. LCGC North America, 2015, 33 (9), pp 718-726. Available from: http://www.chromatographyonline.com/analyzing-trace-levels-carbontetrachloride-drugsubstanceheadspace-gc-flame-ionization-detection [Accessed 10 November 2015]. Books 3. Burgot, J.-L. Ionic Equilibria in Analytical Chemistry. Springer Science & Business Media, New York, 2012, Chapter 11, p 181. 4. Griffiths, W. J.; Ogundare, M.; Meljon, A.; Wang, Y. Mass Spectrometry for Steroid Analysis. In: Mike, S.L. (Ed.). Mass Spectrometry Handbook, v. 7 of Wiley Series on Pharmaceutical Science and Biotechnology: Practices, Applications and Methods. John Wiley & Sons, Hoboken, N.J., 2012, pp 297-338. Standard methods 5. International Organization for Standardization. ISO 26603. Plastics — Aromatic isocyanates for use in the production of polyurethanes — Determination of total chlorine. Geneva, CH: ISO, 2017.
96
Author's Guidelines Master’s and doctoral theses or other academic literature 1. 6. Ek, P. New methods for sensitive analysis with nanoelectrospray ionization mass spectrometry. Doctoral thesis, 2010, School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden. Patents 2. 7. Trygve, R.; Perelman, G. US 9053915 B2, June 9 2015, Agilent Technologies Inc., Santa Clara, CA, US. Web pages 3. 8. http://www.chromedia.org/chromedia [Accessed 21 June 2015]. Unpublished source 9. Mendes, B.; Silva, P.; Pereira, J.; Silva, L. C.; Câmara, J. S. Poster presented at: 36th International 4. Symposium on Capillary Chromatography, 2012, Riva del Garda, Trento, IT. 10. Author, A. A. J. Braz. Chem. Soc., in press. 5. 11. Author, B. B., 2015, submitted for publication. 6. 7. 12. Author, C. C., 2011, unpublished manuscript. Note: Unpublished results may be mentioned only with express authorization of the author(s). Personal communications can be accepted exceptionally. Manuscript submission Three different PDF files, as described below, must be sent online through the website www.brjac.com.br I. A cover letter addressed to the editor-in-chief with the full manuscript title, the full names of the authors and their affiliations, the complete contact information of the corresponding author, including the ORCID iD, and the manuscript abstract. This letter must present why the manuscript is appropriate for publication in BrJAC, and contain a statement that the article has not been previously published and is not under consideration for publication elsewhere. The corresponding author must declare on behalf of all the authors of the manuscript any financial conflicts of interest or lack thereof. This statement should include all potential sources of bias such as affiliations, funding sources and financial or management relationships which may constitute a conflict of interest. When the manuscript belongs to more than one author, the corresponding author must also declare that all authors agree with publication in BrJAC. II.The manuscript file that must NOT mention the names of the authors or the place where the work was performed, but must include the title, abstract, keywords, and all sections of the work, including tables and figures, but excluding acknowledgments that will be included in the final paper upon completion of the review process. III. An analysis report of plagiarism on the manuscript. A Sponsor Report should be sent as a Word file attached to a message to the email brjac@brjac.com.br Revised manuscript submission Based on the comments and suggestions of the reviewers and editors a revision of the manuscript may be requested to the authors. The revised manuscript submitted by the authors must contain the changes made in the manuscript clearly highlighted. A letter without any author's information must also be sent with each reviewer's comment items and a response to each item. Copyright When submitting their manuscript for publication, the authors agree that the copyright will become the property of the Brazilian Journal of Analytical Chemistry, if and when accepted for publication. The copyright comprises exclusive rights of reproduction and distribution of the articles, including reprints, photographic reproductions, microfilms or any other reproductions similar in nature, including translations. Final Considerations
Whatever the nature of the submitted manuscript, it must be original in terms of methodology, information, interpretation or criticism. As to the contents of published articles, the sole responsibility belongs to the authors, and Br. J. Anal. Chem. and its editors, editorial board, employees and collaborators are fully 97
Author's Guidelines
exempt from any responsibility for the data, opinions or unfounded statements BrJAC reserves the right to make, whenever necessary, small alterations to the manuscripts in order to adapt them to the journal rules or make them clearer in style, while respecting the original contents. The article will be sent to the authors for approval prior to publication.
98
rd meeting of the
3
6 ENQ th
Brazilian Society of Forensic Sciences
For
National Meeting of Forensic Chemistry
Integrated Congress
04 to 08 november 2018 Convention Center - Ribeirão Preto - SP - Brazil
"The challenges of Forensic Sciences in the integration between know ledge, intelligence and expert technique" Organized by
Held by
Brazilian Society of Forensic Sciences UN
ER
LO
University of São Paulo IV
U PA S ID ADE DE SÃO
Brazilian Society of Forensic Sciences, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto (FFCLRP), and University of São Paulo (USP)
http://www.sbcf.org.br
January â&#x20AC;&#x201C; March 2018 Volume 5 Number 18