An overview of the detection of benzodiazepines and their respective metabolites and target analytes in urine by LC-MS/MS is described. This overview shows substantial differences in the approach to detection using this technique including optional use of β-glucuronidase to hydrolyze conjugates present in urine. There are also significant variations in the extraction method employed from the use of direct injection, liquid-liquid extraction to solid-phase extraction options, with little apparent difference in limits of detection. Chromatography was largely based on the use of C18-bonded columns; however both C8- and phenyl-bonded columns were used to affect separation. Modern-day tandem mass spectrometers are capable of exceptional sensitivity enabling detection of sub-nanogram per milliliter amounts in urine, which provide for longer detection times in the urine of suspected drug-facilitated assaults. A method employed in the laboratory of the authors is provided by way of an example for readers wishing to establish a method in their own laboratory.
Keywords: Benzodiazepines; Liquid chromatography; Liquid-liquid extraction; Metabolites; Novel psychoactive drugs; Solid-phase extraction; Tandem mass spectrometry; β-Glucuronidase.