Effects of particle size distribution on inductively coupled plasma mass spectrometry signal intensity during laser ablation of glass samples

Abstract

The relation between laser-generated particles and ICPMS signal intensity was investigated using single-pulse laser ablation sampling of solids. The particle size distribution of glass samples was measured using an optical particle counter for different laser ablation conditions. Ablation of a new surface produced fewer particles and lower ICPMS signal intensity than a preablated surface. Laser power density of 0.4-0.5 GW/cm2 was found to be a threshold value, across which particle size distribution changed. Laser beam diameter was a more influential parameter than power density in efficient particle generation. Particle loss during transport from the ablation chamber to the ICPMS was significant for a low carrier gas flow rate of 0.1 L/min, while almost no loss was observed for a higher flow rate of 0.26 L/min. The onset of ICPMS intensity time profiles decreased as more large particles were generated. ICPMS intensity data were calibrated with respect to the particle mass entering the ICPMS. Particle entrainment efficiency of the LA-ICPMS system was estimated and found to be a strong function of laser power density.