title: Metabolism and fate of [(14)C]ethametsulfuron-methyl in rutabaga (Brassica napobrassica Mill).
abstract: The metabolism and fate of ethametsulfuron-methyl ¿methyl 2-[[[[[4-ethoxy-6-(methylamino)-1,3, 5-triazin-2-yl]amino]carbonyl]amino]sulfonyl]benzoate¿ in rutabaga were investigated. After 72 h, absorption and translocation of [(14)C]ethametsulfuron-methyl in rutabaga did not change for the duration of the study (50 days). Less than 4% of recovered radioactivity was present in the rutabaga root. Ethametsulfuron-methyl was metabolized through a proposed unstable alpha-hydroxy ethoxy intermediate that dissipated 3 days after treatment to two major metabolites, O-desethylethametsulfuron-methyl and N-desmethyl-O-desethylethametsulfuron-methyl, as determined by liquid chromatography-mass spectrometry. It was estimated that at a spray dose of 30 g of active ingredient ha(-)(1) and a harvest weight of 0.5 kg, the edible portion of the rutabaga root would contain no ethametsulfuron-methyl and approximately 1.3 ppb total of both identified metabolites. Residue analysis and toxicological assessment show that ethametsulfuron-methyl and its metabolites should pose little or no risk to consumers of rutabagas.
authors.affiliation: Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
authors.forename: L L
authors.initials: LL
authors.lastname: Van Eerd
authors.forename: J C
authors.initials: JC
authors.lastname: Hall
mesh_terms: D000042:Absorption; D001565:Benzoates / Q000378:metabolism*; D001937:Brassica / Q000187:drug effects / Q000378:metabolism*; D006540:Herbicides / Q000378:metabolism*; D013058:Mass Spectrometry; D014227:Triazines / Q000378:metabolism*
chemical_list: D001565:Benzoates; D006540:Herbicides; D014227:Triazines; C413983:methyl 2-(((((4-ethoxy-6-(methylamino)-1,3,5-triazin-2-yl)amino)carbonyl)amino)sulfonyl)benzoate