PNNL

Abstract

Boron (B) isotopes is a valuable tracer with application ranging from geologic, environmental, and nuclear studies because B isotopic fractionation is highly sensitive to chemical processes yielding distinct isotopic trends in natural and anthropogenic systems. Despite this wide applicability, there remain relatively few measurements on well-described reference materials and in some cases, poor agreement between various methods. We report a method for boron isotope ratio measurement in solution on the Neoma MC-ICP-MS/MS specifically targeting bulk silicates. We evaluate the performance of the method and instrument as it relates to the measurement of the absolute boron isotope ratio (10B/11B). Results indicate that the method produces data in agreement with literature values and that the sample-standard bracketing technique is appropriate for the Neoma MC-ICP-MS/MS which has been in use for decades on previous generation instruments. Our results for IAEA B-6, BCR-2, BHVO-2 and W-2a reference materials overlaps 1s range of previously reported 10B/11B. Data are reported for total boron quantities down to a few 10s of nanograms, although blank corrections become important at these levels. We report B isotope ratios for AGV-2G, SL-1G, GSC-2G, GSD-2G, GSE-2G, RLS-132, RLS-140, NKT-1G, and T1-G glass reference materials that have not been previously reported in the literature.