Lithium and Boron Isotope Ratios of Seven Glass Reference Materials (OJY‐1, OH‐1, OA‐1, CGSG‐1, CGSG‐2, CGSG‐4 and CGSG‐5): New Reference Materials for In Situ δ7Li and δ11B Microanalysis

The geochemistry of lithium and boron isotopes is widely applied to a variety of Earth science disciplines. In situ measurement of Li and B isotope ratios requires matrix-matched reference materials for calibration, method validation and inter-laboratory data comparison. In this study, we characterise the Li and B isotope ratios (δ7Li and δ11B) of the seven glass reference materials OJY-1, OH-1, OA-1, CGSG-1, CGSG-2, CGSG-4 and CGSG-5. These seven materials exhibit relative homogeneous δ7Li and δ11B values at the spatial resolution of 10–120 μm, as revealed by multiple spot analyses using LA-MC-ICP-MS (n = 80–100) and SIMS (n = 8–12) on different grains. The 2s of δ7Li and δ11B in these materials as determined by LA-MC-ICP-MS and SIMS ranges from ~ 0.40 to ~ 1.50‰. The recommended δ7Li and δ11B values were determined using solution MC-ICP-MS techniques, and data from independent laboratories showed high precision with discrepancies within ~ 1.50‰. The Li and B mass fractions of the various glasses differ, ranging from ~ 40 μg g-1 to 2000 μg g-1 and ~ 40 μg g-1 to 5000 μg g-1, respectively. The various glasses also have different δ7Li and δ11B values, ranging from +0.99 to +5.69‰ and -10.92 to +0.25‰, respectively. Notably, OA-1 and OH-1 are high-silica glasses (SiO2 > 75% m/m) and, therefore, may be particularly helpful for Li and B isotope analysis of highly evolved magmatic rocks. These investigated glasses have great potential as reference materials for the in situ measurement of Li and B isotope ratios.