Food Matrix Reference Materials for Hydrogen, Carbon, Nitrogen, Oxygen, and Sulfur Stable Isotope-Ratio Measurements: Collagens, Flours, Honeys, and Vegetable Oils

2020 ◽  
Vol 68 (39) ◽  
pp. 10852-10864
Author(s):  
Arndt Schimmelmann ◽  
Haiping Qi ◽  
Philip J. H. Dunn ◽  
Federica Camin ◽  
Luana Bontempo ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Vegetable Oils ◽  
Reference Materials ◽  
Isotope Ratio ◽  
Stable Isotope Ratio ◽  
Food Matrix ◽  
Isotope Ratio Measurements

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

2020 ◽  
Author(s):  
Nives Ogrinc ◽  
Arndt Schimmelmann ◽  
Haiping Qi ◽  
Federica Camin ◽  
Luana Bontempo ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Vegetable Oils ◽  
Reference Materials ◽  
Noble Gas ◽  
Stable Isotope Ratio ◽  
Organic Liquids ◽  
Multiple Point ◽  
Food Matrix ◽  
Consensus Values ◽  
Analytical Approaches

<p>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 δ<sup>2</sup>H<sub>VSMOW</sub> values from −207.4 to −43.3 mUr or ‰, for δ<sup>13</sup>C<sub>VPDB</sub> from −30.60 to −13.72 mUr, for δ<sup>15</sup>N<sub>air</sub> from +1.78 to +14.96 mUr, for δ<sup>18</sup>O<sub>VSMOW</sub> from +18.20 to +26.33 mUr, and for δ<sup>34</sup>S<sub>VCDT</sub> 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 δ<sup>2</sup>H 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 H<sub>2</sub>O 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 δ<sup>2</sup>H variance. Utilization of these new RMs should foster mutual compatibility of δ<sup>2</sup>H values if harmonized technical/analytical approaches are followed and documented in data reports.</p>

Innovative two-step isolation of Ni prior to stable isotope ratio measurements by MC-ICP-MS: application to igneous geological reference materials

2020 ◽  
Vol 35 (10) ◽  
pp. 2213-2223
Author(s):  
Hugues Beunon ◽  
Stepan M. Chernonozhkin ◽  
Nadine Mattielli ◽  
Steven Goderis ◽  
Luc-Serge Doucet ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Reference Materials ◽  
Isotope Ratio ◽  
Stable Isotope Ratio ◽  
Ratio Analysis ◽  
Icp Ms ◽  
Isotope Ratio Analysis ◽  
Stable Isotope Ratio Analysis ◽  
Chromatographic Isolation ◽  
Isotope Ratio Measurements

Simple chromatographic isolation of nickel in just two steps prior to Ni stable isotope ratio analysis by MC-ICP-MS.

A novel sample loading method and protocol for monitoring sample fractionation for high precision Ca stable isotope ratio measurements using double-spike TIMS

2018 ◽  
Vol 33 (1) ◽  
pp. 141-150 ◽  
Author(s):  
Surajit Mondal ◽  
Ramananda Chakrabarti
Keyword(s):  
Mass Spectrometry ◽  
Stable Isotope ◽  
Isotope Ratio ◽  
Thermal Ionization Mass Spectrometry ◽  
Stable Isotope Ratio ◽  
Ionization Mass ◽  
Loading Method ◽  
Thermal Ionization Mass ◽  
Isotope Ratio Measurements ◽  
Better Than

The external reproducibility (2σSD) of Ca stable isotope ratio measurements (δ44/40Ca) using double-spike (43Ca–48Ca) thermal ionization mass spectrometry (TIMS) is better than 0.08 ‰ using our proposed loading technique.

Sign in / Sign up

Export Citation Format

Share Document