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تسجيل

Drug identification , Benzodiazepines

المؤلف:  Sue Jickells , Adam Negrusz (Editors)

المصدر:  Clarkes Analytical Forensic Toxicology

الجزء والصفحة:  161

2026-10-05

151

Drug identification

Benzodiazepines

Surprisingly, until 1995 the chromatographic detection of benzodiazepines in hair did not appear to be documented. Results have been obtained using incubation in buffer, such as Sörensen buffer (Cirimele et al. 1996b; Kintz et al. 1996) or an acetate buffer at pH 4.0 that contains b-glucuronidase arylsulfatase (Yeggles et al. 1997). In most cases, GC-MS in either electron impact (EI) or negative-ion chemical ionisation (NICI) mode was used. However, to detect diazepam, nitrazepam, oxazepam or alprazolam, liquid chromatography with UV detection (HPLC-UV), GC with electron-capture detection (GC-ECD) or liquid chromatography with diode array detection (HPLC-DAD) were employed. An extensive review of analytical procedures to test for benzodiazepines, particularly flunitrazepam, was published in 1998 (Sachs and Kintz 1998). In another study, concentrations of 7-aminoflunitrazepam in two postmortem hair samples were found to be higher than corresponding flunitrazepam levels (Negrusz et al. 1999). The same group demonstrated deposition of clonazepam and its major metabolite 7-aminoclonazepam in hair by negative-ion chemical ionization GC-MS analysis of segmented hair samples collected from people taking therapeutic doses of clonazepam. The study revealed that the 7-amino clonazepam concentrations in hair are higher than concentrations of the parent drug, and it remains in hair for much longer periods of time (Negrusz et al. 2000). The first controlled clinical study with a single dose of flunitrazepam given to volunteers revealed the presence of 7 amino flunitrazepam in hair throughout the 30-day study period (Negrusz et al. 2001). A similar study with a single dose of clonazepam was published by the same group (Negruszetal.2002). As demonstrated by the concentrations found, benzodiazepine concentrations are generally low, in the pg/mg range, which is why NICI GC MS or LC-MS represents the state of the art for the analysis of benzodiazepines in human hair, because of the high electrophilic character of the analytes.