title: Photodegradation of penoxsulam.
abstract: This study was carried out to characterize the photodegradation of penoxsulam and to evaluate the significance of photolysis for its fate and dissipation. Degradation studies of (14)C-labeled isotopes of penoxsulam in a "merry-go-round" reactor suggest that aqueous photodegradation proceeds via three possible pathways: cleavage of the sulfonamide bridge, stepwise degradation of the triazolopyrimidine system and its substituents, and photooxidation of the sulfonyl group. Seven major photoproducts were found, and six were identified. Two of the identified photodegradation products seem to be either rapidly biodegraded when formed or not formed in significant amounts in environmental conditions.
authors.affiliation: Department of Environmental Toxicology, College of Agricultural and Environmental Sciences, University of California, Davis, 95616-8588, USA. thomasj@sfei.org
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Jabusch
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Tjeerdema
mesh_terms: D002250:Carbon Radioisotopes; D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D010782:Photolysis; D013449:Sulfonamides / Q000737:chemistry* / Q000528:radiation effects; D014529:Uridine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000528:radiation effects
chemical_list: D002250:Carbon Radioisotopes; D013449:Sulfonamides; C504402:penoxsulam; D014529:Uridine