NIST RM 8301 Boron Isotopes in Marine Carbonate (Simulated Coral and Foraminifera Solutions): Inter-laboratory 11B and Trace Element Ratio Value Assignment Academic Article uri icon

abstract

  • The boron isotopic ratio of 11B/10B (11BSRM951) 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 interlaboratory comparison study to both assign 11BSRM951 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. Noncertified reference values and expanded 95% uncertainties for 11BSRM951 in NIST RM 8301 (Coral) (+24.170.18) and NIST RM 8301 (Foram) (+14.510.17) solutions were assigned by consensus approach using interlaboratory data. Differences reported among laboratories were considerably smaller than some previous interlaboratory 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/Ca5% RSD) was often greater than within a single laboratory (e.g., Mg/Ca<2%). Such differences potentially alter proxyreconstructed seawater temperature by more than 2C. These now wellcharacterised solutions are useful reference materials to help the palaeoceanographic community build a comprehensive view of past ocean changes.

published proceedings

  • GEOSTANDARDS AND GEOANALYTICAL RESEARCH

author list (cited authors)

  • Stewart, J. A., Christopher, S. J., Kucklick, J. R., Bordier, L., Chalk, T. B., Dapoigny, A., ... Day, R. D.

complete list of authors

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

publisher