title: Trace analysis of quinapril and its active metabolite, quinaprilat, in human plasma and urine by gas chromatography-negative-ion chemical ionization mass spectrometry.
abstract: A highly specific and sensitive method for the simultaneous determination of quinapril and its active metabolite, quinaprilat, in human plasma and urine by gas chromatography-negative-ion chemical ionization mass spectrometry is described. Quinapril and quinaprilat were extracted from human plasma and urine by using a Bond-Elut C18 cartridge. The plasma or urine extract was treated with pentafluorobenzyl bromide followed by trifluoroacetic anhydride to convert quinapril and quinaprilat into their pentafluorobenzyl-trifluoroacetyl derivatives, which were analysed by a selected-ion monitoring method using deuterium-labelled internal standards. The limits of quantitation for both quinapril and quinaprilat were 0.05 ng/ml in plasma and 0.5 ng/ml in urine. The proposed method is applicable to pharmacokinetic and clinical pharmacological studies with satisfactory reliability.
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: Kamata
authors.forename: K
authors.initials: K
authors.lastname: Ikegami
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000097:blood / Q000378:metabolism* / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007477:Ions; D007546:Isoquinolines / Q000097:blood / Q000378:metabolism* / Q000652:urine; D000077583:Quinapril; D044005:Tetrahydroisoquinolines
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D007477:Ions; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; C054501:quinaprilat; D000077583:Quinapril