title: Automated preparation and analysis of barbiturates in human urine using the combined system of PrepStation and gas chromatography-mass spectrometry.
abstract: A system for an automatic sample preparation procedure followed by on-line injection of the sample extract into a gas chromatography-mass spectrometry (GC-MS) system was developed for the simultaneous analysis of seven barbiturates in human urine. Sample clean-up was performed by a solid-phase extraction (SPE) on a C18 disposable cartridge. A SPE cartridge was preconditioned with methanol and 0.1 M phosphate buffer. After loading a 1.5 ml volume of a urine sample into the SPE cartridge, the cartridge was washed with 2.5 ml of methanol-water (1:9, v/v). Barbiturates were eluted with 1.0 ml of chloroform-isopropanol (3:1, v/v) from the cartridge. The eluate (1 microl) was injected into a GC-MS system. The calibration curves, using an internal standard method, demonstrated a good linearity throughout the concentration range from 0.02 to 10 microg/ml for all barbiturates extracted. The proposed method was applied to several clinical cases. The total analysis time for 20 samples was approximately 14 h.
authors.affiliation: Department of Legal Medicine, Hiroshima University School of Medicine, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Namera
authors.forename: M
authors.initials: M
authors.lastname: Yashiki
authors.forename: K
authors.initials: K
authors.lastname: Okada
authors.forename: Y
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: M
authors.initials: M
authors.lastname: Ohtani
authors.forename: T
authors.initials: T
authors.lastname: Kojima
mesh_terms: D000328:Adult; D001463:Barbiturates / Q000145:classification / Q000652:urine*; D002940:Circadian Rhythm; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006993:Hypnotics and Sedatives / Q000145:classification / Q000652:urine*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009862:Online Systems; D015203:Reproducibility of Results
chemical_list: D001463:Barbiturates; D006993:Hypnotics and Sedatives