Modern screening strategies in analytical toxicology with special regard to new benzodiazepines

Abstract

Screening procedures for the detection of toxicologically relevant substances have become of ever-increasing importance due to the rapid development of new substances. Identification methods must be simple, sensitive, and practicable. This article describes standardized chromatographical (corrected Rcf values, retention indices) and immunological methods (enzyme-multiplied immunoassay technique, fluorescent polarization immunoassay) with special regard to the screening of some newer benzodiazepines, a class of substances that is still expanding. Some of these new compounds may be integrated in well-known screening procedures (via aminobenzophenones and detection by the Bratton-Marshall reagent); others require special concepts for detection. The problems are indicated and discussed, including the use of high-pressure-liquid chromatography and mass spectrometry; recommendations are given.

A rapid solid-phase extraction and HPLC/DAD procedure for the simultaneous determination and quantification of different benzodiazepines in serum, blood and post-mortem blood

“…The latter technique is particularly suitable for the quantitative determination of substances with intense UV absorption, such as the 1,4-benzodiazepines, particularly since some of these compounds exhibit thermal instability [23,24]. Although its value as a screening method is still controversial, the combination with diode-array detection has to be considered as a highly effective and selective screening method [25,26]. Solid-phase extraction performed on a bonded silica phase is an alternative to liquid-liquid extraction for the isolation of drugs.…”

Development of a Surface-Enhanced Raman Spectroscopy Method for the Detection of Benzodiazepines in Urine

“…These benzophenones are formed due to the cleavage of the diazepine ring at the N-4 position, causing an open ring structure which can reduce the specificity of the immunoassay. 10,21 Once the sample is prepared, the immunoassay process is performed using an automated plate reader. Careful attention to the quality and quantity of the sample is important as false negatives or false positives can occur, which result from matrix interferences and the presence of other drugs in the patients' system.…”