Simultaneous Bulk-Rock Elemental and Boron Isotope Ratio Measurement Using LA-ICP-MS on Silicate Micro-Particulate Pellets

We have established a method for the simultaneous measurement of element abundances and boron isotopic compositions of bulk-rock silicate samples by laser ablation coupled to two different ICP-MS instruments. Fifteen silicate reference materials were prepared as micro-particulate pressed powder pellets (MP) for analysis. Approximately 1/5th of the ablated material was transported to a single-collector ICP-MS for elemental measurement, while 4/5ths were sent to a multi-collector ICP-MS for boron isotope ratio measurement. Compositions of different milling materials (agate, zirconium oxide, tungsten carbide, sintered corundum and silicon nitride) were measured for the evaluation of potential contamination during sample preparation. Determined element mass fractions are in agreement with literature values within ±20%. For boron isotope ratios, the matrix-dependent background elevation across the m/z from 9.9 to 11, and the effect of ablation mass was quantified. Measured δ¹¹B values of most reference materials are consistent with literature values within ±1‰. The intermediate measurement precision is ±0.3‰ for JB-2 with 30 μg g⁻¹ B and ±0.4‰ for JA-2 with 21 μg g⁻¹ B. A publically available, web-based streamlit app was developed for data processing (https://zenodo.org/doi/10.5281/zenodo.11150471). This paves the way for combined, accurate and precise elemental and boron isotope ratio measurements of geological materials.