title: Determination of valdecoxib and its metabolites in human urine by automated solid-phase extraction-liquid chromatography-tandem mass spectrometry.
abstract: A simple, sensitive and specific automated SPE-LC-MS-MS assay was developed and validated for determination of valdecoxib (I), its hydroxylated metabolite (II) and carboxylic acid metabolite (III) in human urine. The analytes (I, II and III) and a structural analogue internal standard (I.S.) were extracted on a C(18) solid-phase extraction cartridge using a Zymark RapidTrace automation system. The chromatographic separation was performed on a narrow-bore reverse phase HPLC column with a mobile phase of acetonitrile-water (50:50, v/v) containing 10 mM 4-methylmorpholine (pH 6.0). The analytes were ionized using negative electrospray mass spectrometry, then detected by multiple reaction monitoring with a tandem mass spectrometer. The precursor to product ion transitions of m/z 313-->118, m/z 329-->196 and m/z 343-->196 were used to measure I, II and III, respectively. The assay exhibited a linear dynamic range of 1-200 ng/ml for I and II and 2-200 ng/ml for III in human urine. The lower limit of quantitation was 1 ng/ml for I and II and 2 ng/ml for III. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. Run time of 5.5 min for each sample made it possible to analyze a throughput of 70 human urine samples per run. The assay has been successfully used to analyze human urine samples to support clinical phase I and II studies.
authors.affiliation: Global Drug Metabolism, Pharmacia, Skokie, IL 60077, USA. ji.y.zhang@pharmacia.com
authors.forename: Ji Y
authors.initials: JY
authors.lastname: Zhang
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Fast
authors.forename: Alan P
authors.initials: AP
authors.lastname: Breau
mesh_terms: D001331:Automation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D016861:Cyclooxygenase Inhibitors / Q000652:urine*; D006801:Humans; D007555:Isoxazoles / Q000652:urine*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013449:Sulfonamides / Q000652:urine*; D000096926:Benzenesulfonamides
chemical_list: D016861:Cyclooxygenase Inhibitors; D007555:Isoxazoles; D013449:Sulfonamides; C406224:valdecoxib; D000096926:Benzenesulfonamides