title: Determination of dioxopiperazine metabolites of quinapril in biological fluids by gas chromatography-mass spectrometry.
abstract: The dioxopiperazine metabolites of quinapril in plasma and urine were extracted with hexane-dichloroethane (1:1) under acidic conditions. Following derivatization with pentafluorobenzyl bromide and purification of the desired reaction products using a column packed with silica gel, the metabolites were analysed separately by capillary column gas chromatography-electron-impact mass spectrometry with selected-ion monitoring. The limits of quantitation for the metabolites were 0.2 ng/ml in plasma and 1 ng/ml in urine. The limits of detection were 0.1 ng/ml in plasma and 0.5 ng/ml in urine, at a single-to-noise ratio of greater than 3 and greater than 5, respectively. The proposed method is applicable to pharmacokinetic studies.
authors.affiliation: Research Laboratories, Yoshitomi Pharmaceutical Industries, Ltd., Saitama, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Goto
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: M
authors.initials: M
authors.lastname: Shigetoshi
authors.forename: K
authors.initials: K
authors.lastname: Ikegami
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000097:blood / Q000378:metabolism* / Q000652:urine; D004583:Electrons; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007546:Isoquinolines / Q000097:blood / Q000378:metabolism* / Q000652:urine; D000077583:Quinapril; D044005:Tetrahydroisoquinolines
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; C077364:PD 109488; C077363:PD 113413; D000077583:Quinapril