GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC CONFIRMATION OF SELECTED BENZOPHENONES FROM BENZODIAZEPINES IN HUMAN URINE FOLLOWING AUTOMATIC SCREENING

This paper reports a simple, expeditious procedure for confirming the presence of benzodiazepines in previously screened positive urine samp les. Samples are manually hydrolysed to the corresponding benzophenone s in an acid medium. The hydrolysis products are continuously aspirate d into a photometric flow system for screening; positive samples are t hen confirmed and benzodiazepines identified by using a different flow system that conditions the analytes for gas chromatographic separatio n and unequivocal mass spectrometric confirmation. Detection limits fo r benzodiazepines in the nanogram-per-millilitre region are thus achie ved by using 0.5 ml of hydrolysed urine; also, repeatability, as R.S.D ., is less than 6.5%. The high specificity and sensitivity of the prop osed method enables the confirmation of different benzodiazepines in u rine samples obtained from drug addicts and patients from a local hosp ital. (C) 1998 Elsevier Science B.V. All rights reserved.