Precise and Accurate In Situ Determination of Lead Isotope Ratios in NIST, USGS, MPI-DING and CGSG Glass Reference Materials using Femtosecond Laser Ablation MC-ICP-MS

摘要

Lead isotope ratio data were obtained with good precision and accuracy using a 266 nm femtosecond laser ablation (fLA) system connected to a multi-collector ICP-MS (MC-ICP-MS) and through careful control of analytical procedures. The mass fractionation coefficient induced by 266 nm femtosecond laser ablation was approximately 28% lower than that by 193 nm excimer laser ablation (eLA) with helium carrier gas. The exponential law correction method for Tl normalisation with optimum adjusted Tl ratio was utilised to obtain Pb isotopic data with good precision and accuracy. The Pb isotopic ratios of the glass reference materials NIST SRM 610, 612, 614; USGS BHVO-2G, BCR-2G, GSD-1G, BIR-1G; and MPI-DING GOR132-G, KL2-G, T1-G, StHs60/80-G, ATHO-G and ML3B-G were determined using fLA-MC-ICP-MS. The measured Pb isotopic ratios were in good agreement with the reference or published values within 2s measurement uncertainties. We also present the first high-precision Pb isotopic data for GSE- 1G, GSC-1G, GSA-1G and CGSG-1, CGSG-2, CGSG-4 and CGSG-5 glass reference materials obtained using the femtosecond laser ablation MC-ICP-MS analysis technique.