Determination of Alprazolam and α-Hydroxyalprazolam in Human Plasma by Gas Chromatography/Negative-ion Chemical Ionization Mass Spectrometry

Autor: Douglas E. Rollins, Dennis V. Canfield, Dennis J. Crouch, Robert A. A. Maes, Diana G. Wilkins, Karin M. Höld
Rok vydání: 1996
Předmět:
Zdroj: Journal of Mass Spectrometry. 31:1033-1038
ISSN: 1096-9888
1076-5174
DOI: 10.1002/(sici)1096-9888(199609)31:9<1033::aid-jms391>3.0.co;2-h
Popis: A sensitive and specific method was developed for the determination of alprazolam and its major metabolite alpha-hydroxyalprazolam in plasma. After the addition of deuterium-labeled internal standards, plasma samples were buffered to pH 9 with 1 ml of saturated sodium borate buffer, extracted with toluene-methylene chloride (7:3) and evaporated to dryness. The residues were treated with N,O-bis(trimethylsilyl)trifluoroacetamide containing 1% of trimethylchlorosilane and analyzed on a Finnigan-MAT mass spectrometer operated in the negative-ion chemical ionization mode with methane as the reagent gas. Chromatographic separation was achieved on a Restek-200 capillary column using hydrogen as the carrier gas. The assay was linear from 0.25 to 50 ng ml-1 for both compounds. The intra-assay precision for alprazolam was 16.1% at 0.5 ng ml-1 and 4.6% at 50 ng ml-1 and that for alpha-hydroxyalprazolam was 15.8% at 0.5 ng ml-1 and 4.2% at 50 ng ml-1. The method was used to determine alprazolam and alpha-hydroxyalprazolam in human plasma samples collected after a single 2 mg oral does of alprazolam. A peak concentration of 32.9 ng ml-1 of alprazolam was detected at 1 h following the dose.
Databáze: OpenAIRE
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