title: Dissipation of sulfosulfuron in water - bioaccumulation of residues in fish - LC-MS/MS-ESI identification and quantification of metabolites.
abstract: Dissipation study of sulfosulfuron in natural water and its bioaccumulation in fish was conducted at 25+/-2 degrees C and at two different concentration levels 1mgl(-1) and 2mgl(-1). The dissipation data in water showed the DT50 and DT90 values 67-76 and 222-253 days and followed first order kinetics. Bioaccumulation of sulfosulfuron in fish was conducted under static conditions exposing the fish at one-tenth of sub-lethal concentration 9mgl(-1) and at double the concentration 18mgl(-1), for a period of 56 days. On different occasions fish samples were collected and analyzed. A HPLC-RF method was used for the quantification of sulfosulfuron and aminopyrimidine with the limit of quantification 0.001microg ml(-1). Results showed the accumulation of residues of sulfosulfuron in fish over the concentration range 0.009-0.496microg g(-1). Both in water and fish samples, identified the presence of metabolites aminopyrimidine, desmethyl sulfosulfuron, guanidine, sulfonamide, ethyl sulfone and rearranged amine. The formations of these metabolites are confirmed by LC-MS/MS analysis. An LC-MS/MS electro spray ionization technique was used for this purpose. One of the metabolite Aminopyrimidine was identified at higher concentration levels (0.01-0.1microg ml(-1)) when compared with other metabolites. Subsequently dissipation of aminopyrimidine in water and its bioaccumulation was also studied at the concentration level 1mgl(-1) and 2mgl(-1). The calculated DT50 and DT90 values are 66-68 days and 218-226 days, respectively. This followed first order kinetics. Three hundred days after the exposure complete demineralization was observed.
authors.affiliation: Department of Analytical Chemistry, International Institute of Bio-technology and Toxicology (IIBAT), Padappai, Chennai 601 301, Tamil Nadu, India. raamesh_a@hotmail.com
authors.forename: Atmakuru
authors.initials: A
authors.lastname: Ramesh
authors.forename: Sivanandam
authors.initials: S
authors.lastname: Sathiyanarayanan
authors.forename: Loganayagi
authors.initials: L
authors.lastname: Chandran
mesh_terms: D000818:Animals; D002397:Catfishes / Q000378:metabolism*; D002853:Chromatography, Liquid; D013058:Mass Spectrometry; D011743:Pyrimidines / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics*; D021241:Spectrometry, Mass, Electrospray Ionization; D013449:Sulfonamides / Q000493:pharmacokinetics*; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism*
chemical_list: D011743:Pyrimidines; D013449:Sulfonamides; D014874:Water Pollutants, Chemical; D014867:Water; C439268:sulfosulfuron