1. Hydrogen isotope labeling unravels origin of soil-bound organic contaminant residues in biodegradability testing.
- Author
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Lennartz S, Byrne HA, Kümmel S, Krauss M, and Nowak KM
- Subjects
- Glycine metabolism, Glycine analogs & derivatives, Glycine analysis, Glycine chemistry, Glyphosate, Sulfamethoxazole metabolism, Sulfamethoxazole analysis, 2,4-Dichlorophenoxyacetic Acid metabolism, 2,4-Dichlorophenoxyacetic Acid analysis, 2,4-Dichlorophenoxyacetic Acid chemistry, Carbon Isotopes analysis, Amino Acids metabolism, Amino Acids analysis, Amino Acids chemistry, Hydrogen metabolism, Organic Chemicals metabolism, Organic Chemicals analysis, Organic Chemicals chemistry, Biodegradation, Environmental, Soil Pollutants metabolism, Soil Pollutants analysis, Soil Pollutants chemistry, Soil chemistry, Isotope Labeling, Deuterium chemistry, Soil Microbiology
- Abstract
Biodegradability testing in soil helps to identify safe synthetic organic chemicals but is still obscured by the formation of soil-bound 'non-extractable' residues (NERs). Present-day methodologies using radiocarbon or stable (
13 C,15 N) isotope labeling cannot easily differentiate soil-bound parent chemicals or transformation products (xenoNERs) from harmless soil-bound biomolecules of microbial degraders (bioNERs). Hypothesizing a minimal retention of hydrogen in biomolecules, we here apply stable hydrogen isotope - deuterium (D) - labeling to unravel the origin of NERs. Soil biodegradation tests with D- and13 C-labeled 2,4-D, glyphosate and sulfamethoxazole reveal consistently lower proportions of applied D than13 C in total NERs and in amino acids, a quantitative biomarker for bioNERs. Soil-bound D thus mostly represents xenoNERs and not bioNERs, enabling an efficient quantification of xenoNERs by just measuring the total bound D. D or tritium (T) labeling could thus improve the value of biodegradability testing results for diverse organic chemicals forming soil-bound residues., (© 2024. The Author(s).)- Published
- 2024
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