Determination of Lead Isotopes and Trace Elements in Synthetic and Geological Glass Materials (NIST-610, BHVO-2G,...

Laser ablation-high resolution inductively coupled plasma mass spectrometry (LA-HR-ICPMS) offers a powerful in situ analytical technique for determining elemental and isotopic compositions in geological materials. Its potential for precise Pb isotope and trace element analysis at low concentrations, however, requires accurate instrument tuning/optimization and systematic data processing.

We assessed the performance of LA-HR-ICPMS for in situ Pb isotope and trace element measurements in synthetic reference glasses (NIST 610, NIST 612) and geological reference glasses (BHVO-2G, BIR-1G, BCR-2G, TB-1G, GSD-1G) with Pb concentrations as low as 0.4 μg/g. An optimized analytical protocol was developed, involving instrument tuning, background correction, and data reduction procedures to minimize elemental fractionation and enhance analytical precision, accuracy and throughput.

LA-HR-ICPMS achieved Pb isotopic ratios with precision better than ± 3% RSD, consistent with published values, and trace element concentrations with RSDs generally below ± 10%. Elements at higher concentrations exhibit better precision (RSD < ± 3%), while those near detection limits show greater variability. Chondrite-normalized rare earth element (REE) patterns for basaltic glass standards matches well with published data, validating the method's reliability. Comparisons with published solution-based and other in situ datasets confirm the accuracy of our approach.

This study demonstrates that LA-HR-ICPMS provides accurate, precise, and rapid in situ Pb isotopic and trace element determinations, with advantages over conventional wet-chemical methods in terms of minimal sample destruction, high sample throughput, and high spatial resolution. The ability to determine Pb isotopic signatures in basaltic glasses has important implications for constraining mantle dynamics, crustal recycling, provenance determination, and the ore-forming mechanisms.