title: Kinetic studies of endosulfan photochemical degradations by ultraviolet light irradiation in aqueous medium.
abstract: Kinetic studies of endosulfan photochemical degradation in controlled aqueous systems were carried out by ultraviolet light irradiation at lambda = 254 nm. The photolysis of (alpha + beta: 2 + 1) endosulfan, alpha-endosulfan and beta-endosulfan were first-order kinetics. The observed rate constants obtained from linear least-squares analysis of the data were 1 x 10(-4) s(-1); 1 x 10(-4) s(-1); and 2 x 10(-5) s(-1), respectively, and the calculated quantum yields (phi) were 1, 1 and 1.6, respectively. Preliminary differential pulse polarographic (DPP) analysis allowed to observe the possible endosulfan photochemical degradation pathway. This degradation route involves the formation of the endosulfan diol, its transformation to endosulfan ether and finally the ether's complete degradation by observing the potential shifts.
authors.affiliation: Department of Analytical Chemistry, University of Yucatan, Yucatan, Mexico. bquintal@uady.mx
authors.forename: Manuel H
authors.initials: MH
authors.lastname: Barcelo-Quintal
authors.forename: Maria C
authors.initials: MC
authors.lastname: Cebada-Ricalde
authors.forename: Angel R
authors.initials: AR
authors.lastname: Trejo-Irigoyen
authors.forename: Reyna B
authors.initials: RB
authors.lastname: Rendon-Osorio
authors.forename: Jose A
authors.initials: JA
authors.lastname: Manzanilla-Cano
mesh_terms: D004726:Endosulfan / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects*; D007306:Insecticides / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects*; D007700:Kinetics; D010084:Oxidation-Reduction; D010777:Photochemistry / Q000379:methods*; D010782:Photolysis; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays; D014867:Water
chemical_list: D007306:Insecticides; D014867:Water; D004726:Endosulfan