This paper presents a screening procedure for benzodiazepines, which has been developed with special reference to low-dose benzodiazepines such as lorazepam. TLC (thin layer chromatography) acts as the main screening method in this procedure. Final identification is performed by gas chromatography, combined with EC and NP detectors. The TLC technique is very selective and sensitive for benzophenones, hydrolysis products of benzodiazepines. It can be used, for example, to detect low levels of benzodiazepines in the urine specimens of suspected DUI (driving under the influence of alcohol) drivers. TLC can now be automated in various ways. Dual-column gas chromatography analysis has been used to increase the number of drugs detected in a single run. Combined with specific and sensitive EC and NP detectors, it is a powerful tool for detecting and determining benzodiazepines, including lorazepam.
Samenvatting