title: Effect of fulvic acid on the photochemical degradation of methylparathion.
abstract: Photochemical degradation of methylparathion (O,O,-dimethyl O-4 nitrophenylphosphorothioate) in the presence of fulvic acid (FA) between pH 2 and 7 was studied by differential pulse polarography (DPP). Fulvic acid and its photoproducts were not electro-active under the experimental conditions used in this study, and only the pesticide exhibited polarographic signals. Photolysis of methylparathion in acid media was sensitized by fulvic acid since the pesticide did not degrade in the absence of this compound. Methylparathion degradation was observed at each of the studied pHs. The reaction was first-order with rate constant values ranging from 3.3 x 10(-3) to 8.8 x 10(-3)min(-1).
authors.affiliation: Department of Analytical Chemistry, Autonomous University of Yucatan, Mexico. mcano@uady.mx
authors.forename: José A
authors.initials: JA
authors.lastname: Manzanilla-Cano
authors.forename: Manuel H
authors.initials: MH
authors.lastname: Barceló-Quintal
authors.forename: Ligia Del C
authors.initials: Ldel C
authors.lastname: Alcocer-Can
authors.forename: Tania I
authors.initials: TI
authors.lastname: Coral-Martínez
mesh_terms: D001578:Benzopyrans / Q000737:chemistry*; D001673:Biodegradation, Environmental; D006863:Hydrogen-Ion Concentration; D007306:Insecticides / Q000737:chemistry*; D007700:Kinetics; D008743:Methyl Parathion / Q000737:chemistry*; D010777:Photochemistry; D010782:Photolysis
chemical_list: D001578:Benzopyrans; D007306:Insecticides; D008743:Methyl Parathion; C005023:fulvic acid