Barium Isotopic Compositions in Thirty‐Four Geological Reference Materials Analysed by MC‐ICP‐MS

作者：Yajun An, Xin Li, Zhaofeng Zhang · 发表于：Geostandards and Geoanalytical Research · 年份：2019 · DOI：10.1111/ggr.12299 · 被引用次数：29 · 研究领域：Geology and Paleoclimatology Research、Isotope Analysis in Ecology、Geochemistry and Elemental Analysis

Measurement of Ba isotope ratios of widely available reference materials is required for interlaboratory comparison of data. Here, we present new Ba isotope data for thirty‐four geological reference materials, including silicates, carbonates, river/marine sediments and soils. These reference materials (RMs) cover a wide range of compositions, with Ba mass fractions ranging from 6.4 to 1900 µg g −1 , SiO 2 from 0.62% to 90.36% m / m and MgO from 0.08% to 41.03% m / m . Accuracy and precision of our data were assessed by the analyses of duplicate samples and USGS rock RMs. Barium isotopic compositions for all RMs were in agreement with each other within uncertainty. The variation of δ 138/134 Ba in these RMs was up to 0.7‰. The shale reference sample, affected by a high degree of chemical weathering, had the highest δ 138/134 Ba (0.37 ± 0.03‰), while the stream sediment obtained from a tributary draining carbonate rocks was characterised by the lowest δ 138/134 Ba (−0.30 ± 0.05‰). Geochemical RMs play a fundamental role in the high‐precision and accurate determination of Ba isotopic compositions for natural samples with similar matrices. Analyses of these RMs could provide universal comparability for Ba isotope data and enable assessment of accuracy for interlaboratory data.