title: Photodegradation of imidacloprid and fipronil in rice-paddy water.
abstract: Photodegradation of insecticides, imidacloprid and fipronil, in rice-paddy water under the ambient temperature was investigated. The initial concentrations were set at 58.8 and 3.1 μg/L for imidacloprid and fipronil, respectively, according to their reported initial concentrations in the rice-paddy field. The half-lives (DT(50)) of imidacloprid and fipronil were 24.2 and 36.7 h, respectively. Fipronil desulfinyl was detected as a major metabolite and fipronil sulfone was found to be a minor metabolite of fipronil in the photodegradation process. Detected mass of fipronil, fipronil desulfinyl, and fipronil sulfone at 79 h were 12.9%, 45.8%, and 5.2% of initial fipronil mass, respectively.
authors.affiliation: Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Dang Quoc
authors.initials: DQ
authors.lastname: Thuyet
authors.forename: Hirozumi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takagi
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring; D006207:Half-Life; D007093:Imidazoles / Q000032:analysis / Q000737:chemistry*; D007306:Insecticides / Q000032:analysis / Q000737:chemistry*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000032:analysis / Q000737:chemistry*; D012275:Oryza; D055668:Photochemical Processes; D011720:Pyrazoles / Q000032:analysis / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D011720:Pyrazoles; D014874:Water Pollutants, Chemical; C082359:imidacloprid; C082360:fipronil