Kasemann Simone A, Jeffcoate Alistair B, Elliott Tim
Grant Institute of Earth Science, Ion Microprobe Unit, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, Scotland, U.K.
Anal Chem. 2005 Aug 15;77(16):5251-7. doi: 10.1021/ac048178h.
We present data on the lithium isotope compositions of glass reference materials from the United States Geological Survey (USGS) and the National Institute of Standards and Technology (NIST) determined by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS), thermal ionization mass spectrometry (TIMS), and secondary ionization mass spectrometry (SIMS). Our data on the USGS basaltic glass standards agree within 2 per thousand, independent of the sample matrix or Li concentration. For SIMS analysis, we propose use of the USGS glasses GSD-1G (delta(7)Li 31.14 +/- 0.8 per thousand, 2sigma) and BCR-2G (delta(7)Li 4.08 +/- 1.0 per thousand, 2sigma) as suitable standards that cover a wide range of Li isotope compositions. Lithium isotope measurements on the silica-rich NIST 600 glass series by MC-ICPMS and TIMS agree within 0.8 per thousand, but SIMS analyses show systematic isotopic differences. Our results suggest that SIMS Li isotope analyses have a significant matrix bias in high-silica materials. Our data are intended to serve as a reference for both microanalytical and bulk analytical techniques and to improve comparisons between Li isotope data produced by different methodologies.
我们展示了通过多接收电感耦合等离子体质谱法（MC-ICPMS）、热电离质谱法（TIMS）和二次离子质谱法（SIMS）测定的来自美国地质调查局（USGS）和美国国家标准与技术研究院（NIST）的玻璃标准物质的锂同位素组成数据。我们关于USGS玄武岩玻璃标准物质的数据在千分之二以内一致，与样品基质或锂浓度无关。对于SIMS分析，我们建议使用USGS玻璃GSD-1G（δ⁷Li 31.14±0.8‰，2σ）和BCR-2G（δ⁷Li 4.08±1.0‰，2σ）作为合适的标准物质，它们涵盖了广泛的锂同位素组成范围。通过MC-ICPMS和TIMS对富含二氧化硅的NIST 600玻璃系列进行的锂同位素测量在千分之0.8以内一致，但SIMS分析显示出系统的同位素差异。我们的结果表明SIMS锂同位素分析在高硅材料中存在显著的基质偏差。我们的数据旨在为微分析和整体分析技术提供参考，并改善不同方法产生的锂同位素数据之间的比较。
