Stable Isotope Reference Materials and Scale Definitions—Outcomes of the 2024 IAEA Experts Meeting

The participants of the 12<sup>th</sup> International Atomic Energy Agency (IAEA) meeting on stable isotope reference materials reached a consensus, acknowledging the existence and use of two carbon isotope delta scales: the VPDB (Vienna Peedee belemnite) scale and the VPDB-LSVEC (LSVEC - lithium carbonate prepared by H. J. Svec). Conversion models between the two scales can be established and used but introduce uncertainty. A format for isotope delta scale definition was agreed upon and was used to define the two carbon isotope delta scales and the two main oxygen isotope delta scales, VSMOW-SLAP (Vienna Standard Mean Ocean Water-Standard Light Antarctic Precipitation) and VPDB. Confirmation or identification of a second-scale-defining point is still necessary for the nitrogen and sulfur isotope delta scales. Efforts are encouraged to improve consistency among laboratories in the isotopic analysis of "non-exchangeable hydrogen" in bulk organic materials and oxygen in carbonates using the phosphoric acid reaction. Additional topics discussed include (1) need for improvement in reference materials for accurate greenhouse gas isotopic analyses; (2) reference materials under production by the IAEA, the US Geological Survey (USGS), and the US National Institute of Standards and Technology (NIST); (3) methods for value and uncertainty assignment of reference materials; and (4) calculation of carbon-13 isotope delta and oxygen-18 isotope delta of CO<sub>2</sub> measured by dual-inlet isotope ratio mass spectrometry.

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Publication Details

Journal
Rapid Communications in Mass Spectrometry
Published
2025-04-24
DOI
https://doi.org/10.1002/rcm.10018
Citations
11
Primary Topic
Isotope Analysis in Ecology
Type
article
Field-Weighted Citation Impact
18.88
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article

Stable Isotope Reference Materials and Scale Definitions—Outcomes of the 2024 IAEA Experts Meeting

Dinka Besic, Philip J. H. Dunn, Federica Camin, Peter Sperlich et al.
11 citations
Rapid Communications in Mass Spectrometry
Isotope Analysis in Ecology
18.88
article

Stable Isotope Reference Materials and Scale Definitions—Outcomes of the 2024 IAEA Experts Meeting

Dinka Besic, Philip J. H. Dunn, Federica Camin, Peter Sperlich, Jean‐François Hélie, Grzegorz Skrzypek, Joachim Mohn, Robert Wielgosz, Steffen Kümmel, Joële Viallon, Manfred Gröning, Leonard I. Wassenaar, Paul J. Brewer, Heiko Moossen, Rebecca Kraft, Juris Meija, Haiping Qi, Bor Krajnc, Paola Iacumin, Colin E. Allison, Matthias Gehre, Harro A. J. Meijer, Tyler B. Coplen, Zoltán Mester, Sangil Lee
article en
11 citations

Abstract

The participants of the 12<sup>th</sup> International Atomic Energy Agency (IAEA) meeting on stable isotope reference materials reached a consensus, acknowledging the existence and use of two carbon isotope delta scales: the VPDB (Vienna Peedee belemnite) scale and the VPDB-LSVEC (LSVEC - lithium carbonate prepared by H. J. Svec). Conversion models between the two scales can be established and used but introduce uncertainty. A format for isotope delta scale definition was agreed upon and was used to define the two carbon isotope delta scales and the two main oxygen isotope delta scales, VSMOW-SLAP (Vienna Standard Mean Ocean Water-Standard Light Antarctic Precipitation) and VPDB. Confirmation or identification of a second-scale-defining point is still necessary for the nitrogen and sulfur isotope delta scales. Efforts are encouraged to improve consistency among laboratories in the isotopic analysis of "non-exchangeable hydrogen" in bulk organic materials and oxygen in carbonates using the phosphoric acid reaction. Additional topics discussed include (1) need for improvement in reference materials for accurate greenhouse gas isotopic analyses; (2) reference materials under production by the IAEA, the US Geological Survey (USGS), and the US National Institute of Standards and Technology (NIST); (3) methods for value and uncertainty assignment of reference materials; and (4) calculation of carbon-13 isotope delta and oxygen-18 isotope delta of CO<sub>2</sub> measured by dual-inlet isotope ratio mass spectrometry.

Rapid Communications in Mass SpectrometryVol. 39(14)
University of Parma (IT), International Atomic Energy Agency (AT), United States Geological Survey (US), Commonwealth Scientific and Industrial Research Organisation (AU), National Institute of Standards and Technology (US), United States Department of Commerce (US), National Physical Laboratory (GB), Helmholtz Centre for Environmental Research (DE), Université du Québec à Montréal (CA), University of Groningen (NL), The University of Western Australia (AU), Korea Research Institute of Standards and Science (KR), Health Sciences and Nutrition (AU), Wasser Cluster Lunz (AT), Jožef Stefan International Postgraduate School (SI), Max Planck Institute for Biogeochemistry (DE), National Research Council Canada (CA), National Institute of Water and Atmospheric Research (NZ), Swiss Federal Laboratories for Materials Science and Technology (CH), Bureau international des poids et mesures (FR)
Openalex Percentile: Top 1%
Isotope Analysis in Ecology
18.88
DOIOpen Access PDFOpenAlex
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