Cellulose, proteins, starch and simple carbohydrates molecules control the hydrogen exchange capacity of bio-indicators and foodstuffs. (April 2021)

• Record Type: Journal Article
• Authors: Nivesse, A-L.; Baglan, N.; Montavon, G.; Granger, G.; Péron, O.
• Is Part Of: Chemosphere. Volume 269(2021)
• Publication Date: 2021-04
• Subjects: Organically bound tritium -- Hydrogen exchangeability -- Isotopic exchange -- Buried tritium; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128676
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Over the past several years, it has become increasingly acknowledged that Organically Bound Tritium (OBT) is the most pertinent tritium form for understanding its behavior and distribution within the biosphere. The fate of tritium actually depends on the accessibility and exchangeability of hydrogen atoms for isotopic exchanges in natural organic matter, especially in widespread biomass biomolecules like carbohydrates or proteins. The present work is therefore aimed at providing a means for improving the knowledge of tritium speciation and distribution on environmental matrices by evaluating the impact of molecular structure of various carbohydrate molecules on OBT behavior. We are thus proposing to assess the exchange capacities of hydrogen from a gas-solid isotopic exchange methodology in wheat grains, water-milfoil and apple environmental matrices using starch, cellulose/proteins and simple carbohydrates as their respective main constituents. For wheat grains, a good agreement was obtained between experimental and theoretical values as a result of the predominantly simple molecular structure of starch. For both water-milfoil and apple, the disparities between experimental and theoretical values showed the occurrence of the buried form of tritium, correlated with the 3D molecular complexity of their main constituents. The key role played by these determinant constituents on hydrogen exchange capacity could thus be experimentally demonstrated on several environmental matrices. These distinct hydrogen exchange capacities were then proven to exert an influence on the NE-OBT distribution on environmental matrix constituents, in yielding critical information to better the understanding of tritium distribution and behavior in the environment. Highlights: The buried tritium form was detected in both a bio-indicator (water-milfoil) and a food chain sample (apple). The content of buried tritium was correlated with the 3D structure level of starch, cellulose, proteins and simple carbohydrates molecules associations. The key role of the main constituents (starch, cellulose and protein, simple carbohydrates) in influencing hydrogen exchange capacity was experimentally demonstrated. The impact of hydrogen exchangeability on the NE-OBT distribution on environmental matrix constituents was determined. Abstract: