QUANTITATIVE-ANALYSIS OF STEEL SAMPLES WITH LASER IONIZATION MASS-SPECTROMETRY

An analytical method based on sputtering, laser ionization and time-of-flight mass spectrometry is used to determine the composition of stainless-steel samples. Ionization is performed as non-resonant multi-photon ionization, which yields a multi-element mass spectrum. The aim of the method is to investigate the prospects for quantitative analysis. Instrumental sensitivity factors for the various elements are measured by analysing certified reference samples. The concentrations of the most abundant elements in other samples are then measured, using these sensitivity factors, and are found to be within +/- 10 to 15% of the specified compositions. These deviations seem to depend mainly on statistical fluctuations, rather than on any matrix effects. This shows that, to a high degree, sensitivity factors are transferable from one sample to another, provided that the same class of material is studied. This surface analytical method is also useful for the analysis of bulk compositions when the surface of the sample is properly cleaned.