Photo-induced degradation of diuron in aqueous solution by nitrites and nitrates: Kinetics and pathways

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• 作者：M.V. Shankar ; S. Né ; lieu ; L. Kerhoas ; J. Einhorn
• 关键词：Induced phototransformation ; Phenylurea herbicide ; Nitrite ; Nitrate ; Simulated solar irradiation ; Photoproducts
• 刊名：Chemosphere
• 出版年：2007
• 出版时间：January 2007
• 年：2007
• 卷：66
• 期：4
• 页码：767-774
• 全文大小：188 K

文摘

The photo-induced degradation of diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) in aqueous solution under simulated solar irradiation has been investigated in the presence of ions. The degradation rates were compared by varying environmental parameters including substrate and inducer concentrations, oxygen content and pH. The photoproducts were identified by extensive LC–ESI–MS and LC–ESI–MS–MS studies after SPE preconcentration on prepacked cartridges. In both and conditions, oxidation of the N-(CH₃)₂ terminus group is the main process leading to the N-monodemethylated (NHCH₃), N-formyl (N(CH₃)CHO) and the uncommon and unstable carbinolamine (N(CH₃)CH₂OH) by-products. Cl/OH substituted and nitrated phenylureas are formed minorily. Degradation pathways involving OH and (or dimer) radicals as reactive species are proposed.