Quantitative gas chromatographic/mass spectrometric analysis of morphine glucuronides in human plasma by negative ion chemical ionization mass spectrometry.
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.
Leis
Hans Jörg
HJ
University Children's Hospital, Division of Analytical Biochemistry and Mass Spectrometry, Auenbruggerplatz 30, A-8036 Graz, Austria. hans.leis@kfunigraz.ac.at
Fauler
Günter
G
Raspotnig
Günther
G
Windischhofer
Werner
W
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
D000697:Central Nervous System Stimulants; D009022:Morphine Derivatives; C035349:morphine-6-glucuronide; C018108:morphine-3-glucuronide