title: Determination of sulfadimethoxine and 4N-acetylsulfadimethoxine in bovine plasma, urine, oral fluid, and kidney and liver biopsy samples obtained surgically from standing animals by LC/MS/MS.
abstract: A quantitative method was developed and validated to measure the concentration of sulfadimethoxine (SDM) and its major metabolite, (4)N-acetylsulfadimethoxine (AcSDM), in bovine tissues and body fluids. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) gave quantitative results for these two analytes in extracts from bovine plasma, urine, oral fluid, kidney, and liver, using SDM-d(4) as internal standard (I.S.). The lower limit of quantitation (LLOQ) for both analytes in these matrices was validated at 2, 100, and 5 ng/mL in plasma, urine, and oral fluid respectively, and 10 ng/g in both kidney (cortex) and liver. The overall accuracy (average of 4 levels) is, for plasma, 104% (SDM) and 95% (AcSDM), with standard deviation of 9% (SDM) and 15% (AcSDM); for urine, 100% (SDM) and 106% (AcSDM), with standard deviation of 5% (SDM) and 6% (AcSDM); for oral fluid, 103% (SDM) and 103% (AcSDM), with standard deviation of 4% (SDM) and 4% (AcSDM); for kidney, 101% (SDM) and 111% (AcSDM), with standard deviation of 7% (SDM) and 6% (AcSDM); and for liver, 99% (SDM) and 115% (AcSDM), with standard deviation of 11% (SDM) and 9% (AcSDM). C18 SPE cartridges were used to clean-up these matrices, except for urine which was diluted directly with buffer before analysis by LC/MS/MS.
authors.affiliation: Food and Drug Administration, Center for Veterinary Medicine, Laurel, MD 20708, USA. hui.li@fda.hhs.gov
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Smith
authors.forename: O Alberto
authors.initials: OA
authors.lastname: Chiesa
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Kijak
mesh_terms: D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid; D004355:Drug Stability; D007668:Kidney / Q000737:chemistry; D016014:Linear Models; D008099:Liver / Q000737:chemistry; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D013412:Sulfadimethoxine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000097:blood / Q000652:urine; D053719:Tandem Mass Spectrometry
chemical_list: C038180:N(4)-acetylsulfadimethoxine; D013412:Sulfadimethoxine