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A Model Assessment of the Occurrence and Reactivity of the Nitrating/Nitrosating Agent Nitrogen Dioxide ((•)NO(2)) in Sunlit Natural Waters

Nitrogen dioxide ((•)NO(2)) is produced in sunlit natural surface waters by the direct photolysis of nitrate, together with (•)OH, and upon the oxidation of nitrite by (•)OH itself. (•)NO(2) is mainly scavenged by dissolved organic matter, and here, it is shown that (•)NO(2) levels in sunlit surface...

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Autor principal: Vione, Davide
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9370000/
https://www.ncbi.nlm.nih.gov/pubmed/35956802
http://dx.doi.org/10.3390/molecules27154855
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author Vione, Davide
author_facet Vione, Davide
author_sort Vione, Davide
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description Nitrogen dioxide ((•)NO(2)) is produced in sunlit natural surface waters by the direct photolysis of nitrate, together with (•)OH, and upon the oxidation of nitrite by (•)OH itself. (•)NO(2) is mainly scavenged by dissolved organic matter, and here, it is shown that (•)NO(2) levels in sunlit surface waters are enhanced by high concentrations of nitrate and nitrite, and depressed by high values of the dissolved organic carbon. The dimer of nitrogen dioxide (N(2)O(4)) is also formed in the pathway of (•)NO(2) hydrolysis, but with a very low concentration, i.e., several orders of magnitude below (•)NO(2), and even below (•)OH. Therefore, at most, N(2)O(4) would only be involved in the transformation (nitration/nitrosation) of electron-poor compounds, which would not react with (•)NO(2). Although it is known that nitrite oxidation by CO(3)(•)(−) in high-alkalinity surface waters gives a minor-to-negligible contribution to (•)NO(2) formation, it is shown here that NO(2)(−) oxidation by Br(2)(•)(−) can be a significant source of (•)NO(2) in saline waters (saltwater, brackish waters, seawater, and brines), which offsets the scavenging of (•)OH by bromide. As an example, the anti-oxidant tripeptide glutathione undergoes nitrosation by (•)NO(2) preferentially in saltwater, thanks to the inhibition of the degradation of glutathione itself by (•)OH, which is scavenged by bromide in saltwater. The enhancement of (•)NO(2) reactions in saltwater could explain the literature findings, that several phenolic nitroderivatives are formed in shallow (i.e., thoroughly sunlit) and brackish lagoons in the Rhône river delta (S. France), and that the laboratory irradiation of phenol-spiked seawater yields nitrophenols in a significant amount.
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spelling pubmed-93700002022-08-12 A Model Assessment of the Occurrence and Reactivity of the Nitrating/Nitrosating Agent Nitrogen Dioxide ((•)NO(2)) in Sunlit Natural Waters Vione, Davide Molecules Article Nitrogen dioxide ((•)NO(2)) is produced in sunlit natural surface waters by the direct photolysis of nitrate, together with (•)OH, and upon the oxidation of nitrite by (•)OH itself. (•)NO(2) is mainly scavenged by dissolved organic matter, and here, it is shown that (•)NO(2) levels in sunlit surface waters are enhanced by high concentrations of nitrate and nitrite, and depressed by high values of the dissolved organic carbon. The dimer of nitrogen dioxide (N(2)O(4)) is also formed in the pathway of (•)NO(2) hydrolysis, but with a very low concentration, i.e., several orders of magnitude below (•)NO(2), and even below (•)OH. Therefore, at most, N(2)O(4) would only be involved in the transformation (nitration/nitrosation) of electron-poor compounds, which would not react with (•)NO(2). Although it is known that nitrite oxidation by CO(3)(•)(−) in high-alkalinity surface waters gives a minor-to-negligible contribution to (•)NO(2) formation, it is shown here that NO(2)(−) oxidation by Br(2)(•)(−) can be a significant source of (•)NO(2) in saline waters (saltwater, brackish waters, seawater, and brines), which offsets the scavenging of (•)OH by bromide. As an example, the anti-oxidant tripeptide glutathione undergoes nitrosation by (•)NO(2) preferentially in saltwater, thanks to the inhibition of the degradation of glutathione itself by (•)OH, which is scavenged by bromide in saltwater. The enhancement of (•)NO(2) reactions in saltwater could explain the literature findings, that several phenolic nitroderivatives are formed in shallow (i.e., thoroughly sunlit) and brackish lagoons in the Rhône river delta (S. France), and that the laboratory irradiation of phenol-spiked seawater yields nitrophenols in a significant amount. MDPI 2022-07-29 /pmc/articles/PMC9370000/ /pubmed/35956802 http://dx.doi.org/10.3390/molecules27154855 Text en © 2022 by the author. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Vione, Davide
A Model Assessment of the Occurrence and Reactivity of the Nitrating/Nitrosating Agent Nitrogen Dioxide ((•)NO(2)) in Sunlit Natural Waters
title A Model Assessment of the Occurrence and Reactivity of the Nitrating/Nitrosating Agent Nitrogen Dioxide ((•)NO(2)) in Sunlit Natural Waters
title_full A Model Assessment of the Occurrence and Reactivity of the Nitrating/Nitrosating Agent Nitrogen Dioxide ((•)NO(2)) in Sunlit Natural Waters
title_fullStr A Model Assessment of the Occurrence and Reactivity of the Nitrating/Nitrosating Agent Nitrogen Dioxide ((•)NO(2)) in Sunlit Natural Waters
title_full_unstemmed A Model Assessment of the Occurrence and Reactivity of the Nitrating/Nitrosating Agent Nitrogen Dioxide ((•)NO(2)) in Sunlit Natural Waters
title_short A Model Assessment of the Occurrence and Reactivity of the Nitrating/Nitrosating Agent Nitrogen Dioxide ((•)NO(2)) in Sunlit Natural Waters
title_sort model assessment of the occurrence and reactivity of the nitrating/nitrosating agent nitrogen dioxide ((•)no(2)) in sunlit natural waters
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9370000/
https://www.ncbi.nlm.nih.gov/pubmed/35956802
http://dx.doi.org/10.3390/molecules27154855
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