title: Pipette tip solid-phase extraction and gas chromatography - mass spectrometry for the determination of methamphetamine and amphetamine in human whole blood.
abstract: Methamphetamine and amphetamine were extracted from human whole blood samples using pipette tip solid-phase extraction (SPE) with MonoTip C(18) tips, on which C(18)-bonded monolithic silica gel was fixed. Human whole blood (0.1 mL) containing methamphetamine and amphetamine, with N-methylbenzylamine as an internal standard, was mixed with 0.4 mL of distilled water and 50 microL of 5 M sodium hydroxide solution. After centrifugation, the supernatant was extracted to the C(18) phase of the tip (pipette tip volume, 200 microL) by 25 repeated aspirating/dispensing cycles using a manual micropipettor. Analytes retained in the C(18) phase were eluted with methanol by five repeated aspirating/dispensing cycles. After derivatization with trifluoroacetic anhydride, analytes were measured by gas chromatography - mass spectrometry with selected ion monitoring in the positive-ion electron impact mode. Recoveries of methamphetamine and amphetamine spiked into whole blood were more than 87.6 and 81.7%, respectively. Regression equations for methamphetamine and amphetamine showed excellent linearity in the range of 0.5-100 ng/0.1 mL. The limits of detection for methamphetamine and amphetamine were 0.15 and 0.11 ng/0.1 mL, respectively. Intra- and interday coefficients of variation for both stimulants were not greater than 9.6 and 13.8%, respectively. The determination of methamphetamine and amphetamine in autopsy whole blood samples is presented, and was shown to validate the present methodology.
authors.affiliation: Department of Legal Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Tokyo 142-8555, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Hasegawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kumazawa
authors.forename: Xiao-Pen
authors.initials: XP
authors.lastname: Lee
authors.forename: Akemi
authors.initials: A
authors.lastname: Marumo
authors.forename: Natsuko
authors.initials: N
authors.lastname: Shinmen
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Seno
authors.forename: Keizo
authors.initials: K
authors.lastname: Sato
mesh_terms: D000661:Amphetamine / Q000097:blood*; D053593:Forensic Toxicology; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008694:Methamphetamine / Q000097:blood*
chemical_list: D008694:Methamphetamine; D000661:Amphetamine