title: Quantitative gas chromatographic/mass spectrometric analysis of morphine glucuronides in human plasma by negative ion chemical ionization mass spectrometry.
abstract: A sensitive and specific method for the determination of morphine glucuronides in human plasma is presented. Morphine glucuronides, namely morphine-6-glucuronide (M6G) and morphine-3-glucuronide (M3G), were extracted from plasma by solid-phase extraction on C(18) cartridges at pH 9.3 and derivatized to their pentafluorobenzyl ester trimethylsilyl ether derivatives. The compounds were measured by gas chromatography/negative ion chemical ionization mass spectrometry without any further purification. Using this detection mode, a diagnostic useful fragment ion at m/z 748 was obtained at high relative abundance for both target compounds. [(2)H(3)]-labeled morphine glucuronides were used as internal standards. Calibration graphs were calculated by polynomial fit within a range of 10-1280 and 15-1920 nmol l(-1) for the 6- and 3-glucuronide, respectively. At the limit of quantitation (LOQ), the inter-assay precision was 2.21% (M3G) and 2.23% (M6G) and the GC/MS assay variability was 1.8% (M3G) and 0.9% (M6G). The accuracy at the LOQ showed deviations of +4.92% (M3G) and +1.5% (M6G). The sample recovery after solid-phase extraction was 84.7% for both M3G and M6G. The method is rugged, rapid and robust and has been applied to the batch analysis of morphine glucuronides during pharmacokinetic profiling of the drugs.
authors.affiliation: University Children's Hospital, Division of Analytical Biochemistry and Mass Spectrometry, Auenbruggerplatz 30, A-8036 Graz, Austria. hans.leis@kfunigraz.ac.at
authors.forename: Hans Jörg
authors.initials: HJ
authors.lastname: Leis
authors.forename: Günter
authors.initials: G
authors.lastname: Fauler
authors.forename: Günther
authors.initials: G
authors.lastname: Raspotnig
authors.forename: Werner
authors.initials: W
authors.lastname: Windischhofer
mesh_terms: D002138:Calibration; D000697:Central Nervous System Stimulants / Q000032:analysis / Q000097:blood*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D009022:Morphine Derivatives / Q000032:analysis / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000697:Central Nervous System Stimulants; D009022:Morphine Derivatives; C035349:morphine-6-glucuronide; C018108:morphine-3-glucuronide