Laser sampling in inductively coupled plasma mass spectrometry in the inorganic analysis of solid samples: Elemental fractionation as the main source of errors

Resumo

The review is devoted to one of currently most often used methods for the study of the elemental composition of samples differing by origin and matrix, laser sampling (LS), in combination with inductively coupled plasma mass spectrometry. The method ensures the analysis of samples without their transfer into solution and with high spatial resolution, up to several micrometers. The main restriction of laser sampling is due to elemental and isotopic fractionation, proceeding in the interaction of laser irradiance with the sample surface, on which photoelectronic and thermal processes, resulting in the formation of sample aerosols of different nature, can occur depending on the characteristics of laser irradiance. The paper covers works on the study of the effect of the laser wavelength, pulse duration, pulse fluence, plasma screening, explosive boiling, and the crater geometry on elemental fractionation and works in which fractionation coefficients were calculated on the basis of experimental data.