Thin-layer detection of diazepam and/or chilordiazepoxide alone or in combination with major drugs of abuse in drug abuse urine screening programs.

Three extraction procedures for the detection of diazepam, oxazepam, chlorazepate and/or chlordiazepoxide in human urines are presented. All three procedures are based on the acid hydrolysis of benzodiazepines and/or their conjugated metabolites to give the corresponding benzophenones. Procedure I involves the direct acid hydrolysis of raw urine and is recommended when the aim is to test the abuse of benzodiazepine derivatives only. Procedure II Is a two-step extraction method in which a wide variety of drugs of abuse including cocaine (test based on the detection of benzoylecgonine) are extracted by the first step using paper loaded with cation-exchange resin and the benzodiazepines are tested in the second step by the acid hydrolysis of the spent urine left after removing the ion-exchange paper. Procedure III involves the use of inert fibrous matrix and then its acid hydrolysis. The detection procedure is based on the identification of methylaminochlorobenzophenone (MACB) and aminochlorobenzophenone (ACB). MACB is detected as a yellow-colored compound while ACB is detected by spraying with Bratton-Marshall reagent. Specificity of detection of ACB has been achieved by the selection of a thin-layer developing solvent system in which sulfonamides with primary aromatic amino groups remain at the origin.