LALI-TOF-MS Laser Ablation Laser Ionisation Time of Flight Mass Spectrometry

LALI-TOF-MS is a new disruptive analytical technique pioneered by EXUM Instruments for rapid chemical characterisation of solid materials. It was developed to address the challenges associated with existing techniques such as expense, complexity and time required. It provides quantitative chemical analysis with trace element sensitivity. Now available in the MASSBOX, LALI-TOF-MS comes in a compact easy-to- use system and industrial users can bring the analysis in-house saving time and money.

EXUM Instruments Massbox - LALI-TOF-MS Laser ablation laser induced time of flight mass spectrometer

LALI-TOF-MS Overview

LALI-TOF-MS provides high versatility, high-throughput, broad elemental coverage and low detection limits and 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.

Basic Principles of LALI-TOF-MS

Laser Ablation (LA) – Oriented perpendicular to the sold sample’s surface, the first laser ablates, or releases material.
Laser Ionisation (LI) – The second laser ionises material from within the neutral particle cloud.
Time of Flight (TOF) Mass Analysis – After ionisation, the particles move through the optics system to the TOF mass analyser, which measures the difference in time required for ions of different masses to impact a detector.

LALI-TOF-MS Laser Ablation Laser Ionisation Time of Flight Mass Spectrometry schematic

In addition, LALI-TOF-MS can provide:

Chemical mapping with a resolution from 5-200µm
Depth profiling
Rapid screening

LALI-TOF-MS vs Traditional Techniques

	Ease of Use	Light Elements	Metallic Elements	Sensitivity	Speed	Chemical Mapping	Quantitative
MASSBOX	○	○	○	○	○	○	○
LA-ICP-MS			○	○		○	○
ICP-MS^*			○	○			○
Inert gas fusion/combustion	◒	○			○		○
XRF	◒		○		○		◒
SEM-EDX	○	◒	○		○	◒

LALI-TOF-MS Sensitivity Comparison

Example – 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.

LALI-TOF-MS Laser Ablation Laser Ionisation Time of Flight Mass Spectrometry of a nickel alloy CRM

As can be seen there is excellent agreement between the LALI-TOF-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 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