A New Mass Spectrometry Alternative

By Dr. Cameron Chai and Peter Airey

Do you have solid samples and need to know their chemical composition? If you are interested in a hassle-free method that can generate results with trace-level sensitivity in just minutes and are fed up with the limitations of existing mass spectrometry and other chemical analysis technologies read on.

LALI-TOF-MS

LALI-TOF-MS which is short for Laser Ablation Laser Ionisation

Time of Flight Mass Spectrometry is the brainchild of Jeff Williams, founder of EXUM Instruments. As a researcher, he was frustrated with the complexity, time required and limitations of existing technologies, and so developed LALI-TOF-MS.

LALI-TOF-MS provides high versatility, high-throughput, broad elemental coverage and low detection limits and requires virtually no sample preparation. As such it has the potential to disrupt existing chemical analysis techniques used in academia and industry across sectors such as pharmaceuticals, mining and minerals to materials science and batteries.

How Does LALI-TOF-MS Work?

LALI uses one laser to remove material from a solid sample and a second laser to subsequently ionise neutrals. The ability to analyse solid samples avoids the need for complex digestion and calibration requirements, simplifying sample preparation. Furthermore, by targeting neutral particles, the ionisation technique removes many of the matrix effects and interferences that plague traditional plasma-ionising methods.

After ionisation, the TOF mass analyser creates a full mass spectrum at each laser spot. The entire process is performed under vacuum, greatly improving ion transmission efficiency compared to other techniques. There is also no need for inert gas, minimising running costs.

What Can LALI-TOF-MS Tell You?

LALI-TOF-MS can provide you with:

1. Chemical mapping with a resolution from 5-200µm

2. Depth profiling

3. Rapid screening - including pass/ fail analysis

Case Study – Nickel Alloy Analysis

In this example 2 Nickel alloy CRMs were analysed, where one was treated as an unknown. Samples analysed using 3 x 0.2mm² raster areas.

As can be seen there is excellent agreement between the LALITOF-MS analysis and the certified values. The average accuracy for quantified elements is 12%. Excluding outlier W, the average accuracy is 8%, while internal precision is 4%, indicating the technique has excellent repeatability.

Summary

LALI-TOF-MS is a promising new chemical analysis technique available in the Exum Instruments Massbox.

It is suited to research, quality control and failure analysis with results matching those of traditional analytical methods. It is ideal for:

· Quantifying low mass elements (e.g., carbon, oxygen, etc.), trace elements, and metallic constituents in the same analytical session

· Directly analysing solid materials and pelletised powders without complicated sample prep.

· Determining chemical distributions and homogeneity

· Investigating elemental composition as a function of depth e.g. analysis of coatings or plated materials