Laser sampling: Implications for matrix effect in the analysis of laser ablation inductively coupled plasma mass spectrometry

Abstract

To investigate the matrix effect in the analysis of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), a 193-nm ArF ns-LA-ICP-MS is used to quantitatively analyze 46 trace elements in United States Geological Survey (USGS) samples (BCR-2G, BHVO-2G, BIR-1G, and GSD-1G). The relative deviations of most trace elements are within 5% for the matrix-matched calibration (external standard sample GSE-1G). For the non-matrix-matched calibration (external standard sample NIST610), the relative deviations of most volatile elements are within 10%, while the relative deviations of most refractory elements are between −10% and −30%, indicating that the contents of refractory elements are underestimated. Contrary to NIST 610, the deposited ablation particles at the bottom of ablation craters, the ablation depth under different laser fluence, and the characteristics (shock wave (SW) radius, pressure, and temperature) of ablation plumes, for USGS samples are more similar to each other. The laser sampling from different matrix samples will directly determine the final analysis accuracy of LA-ICP-MS.