title: LC-MS/MS method for the determination of carbamathione in human plasma.
abstract: Liquid chromatography-tandem mass spectrometry methodology is described for the determination of S-(N,N-diethylcarbamoyl)glutathione (carbamathione) in human plasma samples. Sample preparation consisted of a straightforward perchloric acid medicated protein precipitation, with the resulting supernatant containing the carbamathione (recovery ~98%). For optimized chromatography/mass spec detection a carbamathione analog, S-(N,N-di-i-propylcarbamoyl)glutathione, was synthesized and used as the internal standard. Carbamathione was found to be stable over the pH 1-8 region over the timeframe necessary for the various operations of the analytical method. Separation was accomplished via reversed-phase gradient elution chromatography with analyte elution and re-equilibration accomplished within 8 min. Calibration was established and validated over the concentration range of 0.5-50 nM, which is adequate to support clinical investigations. Intra- and inter-day accuracy and precision determined and found to be <4% and <10%, respectively. The methodology was utilized to demonstrate the carbamathione plasma-time profile of a human volunteer dosed with disulfiram (250 mg/d). Interestingly, an unknown but apparently related metabolite was observed with each human plasma sample analyzed.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047, USA.
authors.forename: Anthonius A M
authors.initials: AA
authors.lastname: Heemskerk
authors.forename: Leon
authors.initials: L
authors.lastname: van Haandel
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Woods
authors.forename: Elinore F
authors.initials: EF
authors.lastname: McCance-Katz
authors.forename: Todd D
authors.initials: TD
authors.lastname: Williams
authors.forename: John F
authors.initials: JF
authors.lastname: Stobaugh
authors.forename: Morris D
authors.initials: MD
authors.lastname: Faiman
mesh_terms: D000427:Alcohol Deterrents / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid; D004221:Disulfiram / Q000493:pharmacokinetics; D005260:Female; D005978:Glutathione / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D050217:Metabolic Detoxication, Phase II; D008875:Middle Aged; D011355:Prodrugs / Q000493:pharmacokinetics; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D000427:Alcohol Deterrents; D011355:Prodrugs; D016194:Receptors, N-Methyl-D-Aspartate; C546728:carbamathione; D005978:Glutathione; D004221:Disulfiram