title: Fate and degradation of triasulfuron in soil and water under laboratory conditions.
abstract: The behavior and fate of triasulfuron (TRS) in water and soil systems were examined in laboratory studies. The degradation of TRS in both buffer solution and soil was highly pH-sensitive. The rate of degradation could be described with a pseudo first-order kinetic and was much faster at pH 4 than at pH 7 and 9. Aqueous hydrolysis occurred by cleavage of the sulfonylurea bridge to form 2-(2-chloroethoxy) benzenesulfonamide (CBSA) and [(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] (AMMT). AMMT was unstable in aqueous solutions in any pH condition but it degraded more quickly at pH 4 and 9. CBSA did not degrade in aqueous solutions or in enriched cultures but it underwent a quick degradation in the soil. The rates of TRS degradation in sterile and non-sterile soils were similar, suggesting that microorganisms played a minimal role in the breakdown process. This hypothesis is supported by the results of studies on the degradation of TRS by enriched cultures during which the molecule underwent a prevalently chemical degradation.
authors.affiliation: Universita degli Studi di Catania, Dipartimento di Scienze Agronomiche, Catania, Italy. mara.gennari@unito.it
authors.forename: Mara
authors.initials: M
authors.lastname: Gennari
authors.forename: Cristina
authors.initials: C
authors.lastname: Abbate
authors.forename: Andrea
authors.initials: A
authors.lastname: Baglieri
authors.forename: Michele
authors.initials: M
authors.lastname: Negre
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D006540:Herbicides / Q000032:analysis* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D013058:Mass Spectrometry; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D013453:Sulfonylurea Compounds / Q000032:analysis* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism; D000096926:Benzenesulfonamides
chemical_list: D006540:Herbicides; D012989:Soil Pollutants; D013453:Sulfonylurea Compounds; D014874:Water Pollutants, Chemical; C094039:triasulfuron; D000096926:Benzenesulfonamides