Simultaneous determination of common benzodiazepines in blood using capillary gas chromatography

Blood samples were extracted with n-butyl acetate, and the extracts analysed by capillary gas chromatography using DB-1 and DB-1701 capillary columns with electron-capture detection. The DB-1701 column was found to give better separation of different benzodiazepines (BZDs). Recoveries ranged from 79 to 98%. Detection limits ranged from 0.005 to 0.015 microM for triazolam and flunitrazepam, and from 0.02 to 0.1 microM for other BZDs. Data on accuracy and precision are given for diazepam, desmethyldiazepam, flunitrazepam and nitrazepam.