A mechanistic study of the photodegradation of herbicide 2,4,5-trichlorophenoxyacetic acid in aqueous solution.

Maria P Yurkova, Ivan P Pozdnyakov, Victor F Plyusnin, Vycheslav P Grivin, Nikolay M Bazhin, Alexandr I Kruppa, Tatiana A Maksimova

Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., 630090 Novosibirsk, Russian Federation.

Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 2013 Apr

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Photodegradation of herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in aqueous solution was investigated by stationary (254 nm) and nanosecond laser (266 nm) flash photolysis techniques. It was shown that in the primary photochemical step both photoionization (which generates a hydrated electron-radical cation pair) and heterolytic cleavage of a C-Cl bond takes place. The major products of substitution of one of the chlorine atoms in the 2-, 4- or 5-position by a hydroxyl group as well as the products of hydroxylation of the benzene ring in 3- and 6-positions were identified by HPLC and LC-MS methods. The complexation of 2,4,5-T with β- and γ-cyclodextrins (β(γ)CD) was investigated. The influence of such complexation on the quantum yield of herbicide photolysis and on the ratio of photodegradation products was determined.

Citation

Maria P Yurkova, Ivan P Pozdnyakov, Victor F Plyusnin, Vycheslav P Grivin, Nikolay M Bazhin, Alexandr I Kruppa, Tatiana A Maksimova. A mechanistic study of the photodegradation of herbicide 2,4,5-trichlorophenoxyacetic acid in aqueous solution. Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology. 2013 Apr;12(4):684-9