GC/MS analysis of five common benzodiazepine metabolites in urine as tert-butyl-dimethylsilyl derivatives.
A method for the GC/MS confirmation of oxazepam, nordiazepam, desalkylflurazepam, temazepam, and alpha-hydroxyalprazolam in urine is described. The method incorporates a solid phase extraction technique developed by Varian which was found to extract all five metabolites with recoveries exceeding 73%. The extracted metabolites were derivatized with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA), resulting in the formation of stable tert-butyldimethylsilyl (TBDMS) derivatives. Quantitation was performed by GC/MS using oxazepam-D5, nordiazepam-D5, and alpha-hydroxyalprazolam-D5 as internal standards. The method was found to be linear over the range of 50-2000 ng/mL. Within-run precision, measured as the coefficient of variation at 100 ng/mL, was less than 3% for all analytes except temazepam which was 6% (N = 20).
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POISONLAB Inc., San Diego, CA 92111.
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D001569:Benzodiazepines / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007202:Indicators and Reagents; D017646:Organosilicon Compounds; D012015:Reference Standards; D012825:Silicon / Q000652:urine*
D007202:Indicators and Reagents; D017646:Organosilicon Compounds; C009660:t-butyldimethylsilyl compounds; D001569:Benzodiazepines; D012825:Silicon