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

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.