title: Optimization of LC-MS/MS using triple quadrupole mass analyzer for the simultaneous analysis of carbosulfan and its main metabolites in oranges.
abstract: This paper describes an analytical method involving a simple solvent extraction for the simultaneous liquid chromatography coupled to quadrupole tandem mass spectrometry (LC-MS/MS) determination of carbosulfan, its most toxic metabolite--carbofuran--, and its other main metabolites--3-hydroxycarbofuran, 3-ketocarbofuran, 3-hydroxy-7-phenolcarbofuran, 3-keto-7-phenolcarbofuran, 7-phenolcarbofuran and dibutylamine--in oranges. Chromatography was performed on a Zorbax Bonus-RP (150 mm x 2.1 mm, 5 microm). The mobile phase was a ternary gradient water-methanol-acetonitrile with 1.0 mM ammonium acetate at flow rate of 0.2 ml min(-1). The LC separation and MS/MS optimization were studied to select the most appropriate operating conditions. The method developed has also been validated. The limits of quantification (LOQs) were from 1 microg kg(-1) for carbofuran to 10 microg kg(-1) for 3-keto-7-phenolcarbofuran. Extracts spiked with carbosulfan and its metabolites, at LOQ level, yielded average recoveries in the range 60-94%, with relative standard deviations (R.S.D.s) less than 15%. Calibration curves for carbosulfan and its metabolites (range LOQ-1000LOQ) were linear, with coefficients of correlations better than 0.990. The method was successfully applied to establish the primary degradation products in oranges treated with carbosulfan. The LC-MS/MS method developed is simple, rapid, and suitable for the quantification and confirmation of carbosulfan and seven of its main metabolites in orange at levels lower than 10 microg kg(-1).
authors.affiliation: Laboratori de Bromatologia i Toxicologia, Facultat de Farmàcia, Universitat de València, Av. Vicent Andrés Estellés s/n, 46100 Burjassot, València, Spain. carla.soler@uv.es
authors.forename: Carla
authors.initials: C
authors.lastname: Soler
authors.forename: Brett
authors.initials: B
authors.lastname: Hamilton
authors.forename: Ambrose
authors.initials: A
authors.lastname: Furey
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: James
authors.forename: Jordi
authors.initials: J
authors.lastname: Mañes
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Picó