Lithium Isotope Composition of Basalt Glass Reference Material

• Published in: Analytical chemistry (Washington) Vol. 77; no. 16; pp. 5251 - 5257
• Main Authors: Kasemann, Simone A, Jeffcoate, Alistair B, Elliott, Tim
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.08.2005
• Subjects: Analytical chemistry; Chemistry; Exact sciences and technology; Geology; Glass - chemistry; Ions - chemistry; Isotopes; Isotopes - analysis; Isotopes - chemistry; Lithium; Lithium - analysis; Lithium - chemistry; Mass Spectrometry; Minerals - chemistry; Reference Standards; Silicates - chemistry; Spectrometric and optical methods; Temperature; Isotopic analysis; Coupled method; Bias; Microanalysis; Glass; Lithium; Secondary ion mass spectrometry; Inductive coupling plasma spectrometry; Silica; Thermal ionization; Reference material; Basalts; Mass spectrometry; Comparative study
• ISSN: 0003-2700; 1520-6882
• 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‰, independent of the sample matrix or Li concentration. For SIMS analysis, we propose use of the USGS glasses GSD-1G (δ7Li 31.14 ± 0.8‰, 2σ) and BCR-2G (δ7Li 4.08 ± 1.0‰, 2σ) 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‰, 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.