EGU2020-22332
https://doi.org/10.5194/egusphere-egu2020-22332
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Upcoming food matrix stable isotope reference materials from the USGS: honeys, vegetable oils, flours, and collagens

Nives Ogrinc1, Arndt Schimmelmann2, Haiping Qi3, Federica Camin4, Luana Bontempo4, Doris Potočnik1, Aiman Abrahim5, Andrew Cannavan5, James F. Carter6, Philip J.H. Dunn7, Lauren T. Reid3, and Tyler B. Coplen3
Nives Ogrinc et al.
  • 1Jožef Stefan Institute, Department of Environmental Sciences, Ljubljana, Slovenia (nives.ogrinc@ijs.si)
  • 2Indiana University, Department of Earth and Atmospheric Sciences, Bloomington, Indiana, USA
  • 3U.S. Geological Survey, Reston, Virginia, USA
  • 4Food Quality and Nutrition Department, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige (TN), Italy
  • 5Food and Environmental Protection Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Seibersdorf, Austria
  • 6Health Support Queensland, QH Forensic and Scientific Services, Coopers Plains, Brisbane, Australia
  • 7National Measurement Laboratory, LGC Ltd., Teddington, Middlesex, United Kingdom

An international project developed, quality-tested, and measured isotope−delta values of 10 new food matrix reference materials (RMs) for hydrogen, carbon, nitrogen, oxygen, and sulfur stable isotope-ratio measurements to support food authenticity testing and food provenance verification. These new RMs will enable users to normalize measurements of samples to isotope−delta scales. The RMs span a range of δ2HVSMOW values from −207.4 to −43.3 mUr or ‰, for δ13CVPDB from −30.60 to −13.72 mUr, for δ15Nair from +1.78 to +14.96 mUr, for δ18OVSMOW from +18.20 to +26.33 mUr, and for δ34SVCDT from −20.25 to +17.49 mUr. The RMs include (i) a pair of honeys from Canada and tropical Vietnam, (ii) flours from C3 (rice) and C4 (millet) plants, (iii) four vegetable oils from C3 (olive, peanut) and C4 (corn) plants, and (iv) collagen powders from marine fish and terrestrial mammal origins. After thorough homogenization of the bulk materials, multiple aliquots were sealed in glass under vacuum or noble gas to exclude oxygen and to potentially extend the shelf life to decades when stored at –18 °C in the dark. A total of six laboratories from five countries used various analytical approaches and instrumentation for two- or multiple-point isotopic normalization against international RMs. The use of reference waters and organic liquids in silver tubes allowed direct normalization of δ2H values of organic materials against isotopic reference waters following the principle of identical treatment, minimizing interference from atmospheric moisture. An errors-in-variables regression model that included the uncertainty associated with the measured and assigned values of the RMs was applied centrally to normalize results and obtain consensus values and measurement uncertainties reported here for new RMs USGS82 to USGS91. Because of exchangeable hydrogen and H2O in some RMs (especially in honeys, collagens, and flours), sample loading in contact with laboratory air and different types of pre-treatment can result in significant bulk δ2H variance. Utilization of these new RMs should foster mutual compatibility of δ2H values if harmonized technical/analytical approaches are followed and documented in data reports.

How to cite: Ogrinc, N., Schimmelmann, A., Qi, H., Camin, F., Bontempo, L., Potočnik, D., Abrahim, A., Cannavan, A., Carter, J. F., Dunn, P. J. H., Reid, L. T., and Coplen, T. B.: Upcoming food matrix stable isotope reference materials from the USGS: honeys, vegetable oils, flours, and collagens, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22332, https://doi.org/10.5194/egusphere-egu2020-22332, 2020

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Presentation version 2 – uploaded on 05 May 2020 , no comments
Include the title on slides 15-18 and correct the therm on slide 20 to “stock supplies”.
Presentation version 1 – uploaded on 02 May 2020 , no comments