NIST RM 8301 Boron Isotopes in Marine Carbonate (Simulated Coral and Foraminifera Solutions): Inter-laboratory δ11B and Trace Element Ratio Value Assignment

Joseph A. Stewart, Steven J. Christopher, John R. Kucklick, Louise Bordier, Thomas B. Chalk, Arnaud Dapoigny, Eric Douville, Gavin L. Foster, William R. Gray, Rosanna Greenop, Marcus Gutjahr, Freya Hemsing, Michael J. Henehan, Philip Holdship, Yu Te Hsieh, Ana Kolevica, Yen Po Lin, Elaine M. Mawbey, James W.B. Rae, Laura F. RobinsonRachael Shuttleworth, Chen Feng You, Shuang Zhang, Russell D. Day

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


The boron isotopic ratio of 11B/10B (δ11BSRM951) and trace element composition of marine carbonates are key proxies for understanding carbon cycling (pH) and palaeoceanographic change. However, method validation and comparability of results between laboratories requires carbonate reference materials. Here, we report results of an inter-laboratory comparison study to both assign δ11BSRM951 and trace element compositions to new synthetic marine carbonate reference materials (RMs), NIST RM 8301 (Coral) and NIST RM 8301 (Foram) and to assess the variance of data among laboratories. Non-certified reference values and expanded 95% uncertainties for δ11BSRM951 in NIST RM 8301 (Coral) (+24.17‰ ± 0.18‰) and NIST RM 8301 (Foram) (+14.51‰ ± 0.17‰) solutions were assigned by consensus approach using inter-laboratory data. Differences reported among laboratories were considerably smaller than some previous inter-laboratory comparisons, yet discrepancies could still lead to large differences in calculated seawater pH. Similarly, variability in reported trace element information among laboratories (e.g., Mg/Ca ± 5% RSD) was often greater than within a single laboratory (e.g., Mg/Ca < 2%). Such differences potentially alter proxy-reconstructed seawater temperature by more than 2 °C. These now well-characterised solutions are useful reference materials to help the palaeoceanographic community build a comprehensive view of past ocean changes.

Original languageEnglish
JournalGeostandards and Geoanalytical Research
Publication statusAccepted/In press - 2020

All Science Journal Classification (ASJC) codes

  • Geology
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'NIST RM 8301 Boron Isotopes in Marine Carbonate (Simulated Coral and Foraminifera Solutions): Inter-laboratory δ<sup>11</sup>B and Trace Element Ratio Value Assignment'. Together they form a unique fingerprint.

Cite this