Flow-injection fluorimetric determination of 1,4-benzodiazepines in pharmaceutical formulations after acid hydrolysis

A simple, rapid and fully automated flow injection method with fluorimetric detection after hydrolysis with H2SO4 in ethanolic or methanolic medium at room temperature has been developed for the determination of 1,4-benzodiaz epines (oxazepam, diazepam and nitrazepam) in pharmaceutical formulations. The calibration curves are linear in the ranges (mg ml(-1)) of oxazepam (0. 025-0.150), diazepam (0.010-0.125) and nitrazepam (0.010-0.150), with detec tion limits of 0.01, 0.005 and 0.005 mg ml(-1), respectively, and RSD (1% ( n = 10). The measurement throughput is 60 h(-1) using a 200-mu l sample vol ume obtained by the direct dissolution of formulations in alcohol. (C) 1999 Elsevier Science B.V. All rights reserved.