Liquid Chromatographic Separation of Some Common Benzodiazepines and their Metabolites

Abstract A series of benzodiazepines commonly encountered in forensic samples were separated using isocratic reversed-phase liquid chromatography. These compounds display a wide range of capacity factors on a C18 stationary phase in a pH 8 phosphate buffer and methanol mobile phase. Clorazepate must be analyzed under basic mobile phase conditions to prevent its decomposition to N-desmethyldiazepam. The separation of common parent benzodiazepines such as chlordiazepoxide, diazepam and flurazepam from their corresponding metabolites was achieved under a variety of reversed-phase conditions.