Calibration Studies on Dried Aerosols for Laser Ablation–Inductively Coupled Plasma Mass Spectrometry

Abstract

A simultaneous dried solution aerosol (Mistral nebulizer/aerosol dryer) and laser-induced aerosol introduction system was used to investigate the calibration capabilities of dried solutions for LA–ICP-MS. Gas flow rates for the simultaneous systems were optimized and gave the best results with 0.5 l min ^-1 for the laser gas flow rate and 0.5 l min ^-1 for the solution gas flow rate, at which a sensitivity of 65–80% for LA compared with 1.05 l min ^-1 single gas flow LA–ICP-MS was maintained. The optimum temperatures for the Mistral nebulizer were 143 °C (heating) and -3 °C (cooling). Oxide formation (CeO ⁺ /Ce ⁺ ) under these conditions is less than 0.3%. Introduction of enriched ²⁰⁷ Pb (as a solution) and natural lead ( via LA) allows the optimization of both sample introduction systems separately. Analyses were performed on synthetic polyethylene materials, IAEA Soil-7 and CSB-1 reference standards. The RSDs on two sample pellets with five replicates each were better than 10%. Quantitative analyses for all REEs were based on In as the internal standard and Rh as the reference element. Fractionation effects of the internal standard relative to the REE were not observed.