The extraction and analysis of benzodiazepines in tissues by enzymic digestion and high-performance liquid chromatography.

A simple, rapid and sensitive method is described for the analysis of unchanged benzodiazepine drugs and their metabolites, in human and animal tissues, using the proteolytic enzyme subtilisin Carlsberg followed by reverse-phase liquid chromatography. The enzymic digestion yields far higher recoveries than conventional extraction methods, while the liquid chromatogrpahic analysis allows the rapid separation and detection of nanogram quantities of these drugs without the need for elaborate "clean-up" procedures.