Dariusz BŁACHUT¹, Marta BYKAS-STRĘKOWSKA¹, Ewa TARACHA², Bogdan SZUKALSKI^2
1Department of Criminalistics, Internal Security Agency, Warsaw
²Department of Neurochemistry, Institute of Psychiatry and Neurology, Warsaw

A gas-chromatographic-mass spectrometric method was developed for the simultaneous analysis of 18 benzodiazepines in human urine. Separation of this complex mixture of benzodiazepines was achieved on three capillary columns with phases: SPB-OCTYL, SPB-1, HP-5MS.  The thermal instability of benzodiazepines in the chromatographic process may lead to erroneous interpretation of obtained results. This is especially significant in the case of examinations carried out within the framework of expert casework requested by the administration of justice, and thus potentially influencing the outcome of legal proceedings.
The practical usefulness of the developed conditions was checked by means of urinalysis of two patients from the Neurosis Clinic and one patient undergoing methadone treatment at the Department of Detoxification of Institute of Psychiatry and Neurology. Screening tests carried out on these patients to check abstinence compliance revealed compounds from the benzodiazepine group. The urine of the patients from the Neurosis Clinic contained tetrazepam and nordiazepam, whereas that of the patient undergoing methadone therapy contained nordiazepam, amphetamine, promethazine and three of its metabolites, nicotine and three of its metabolites, a metabolite of carbamazepine and also methadone and its two metabolites.

Benzodiazepine; Decomposition; Gas chromatography/Mass spectrometry.