DETERMINATION OF 8-CHLORO-6-(2-FLUOROPHENYL)-1-METHYL-4H-IMIDAZO[1,5-A][1,4]BENZODIAZEPINE BY ADSORPTIVE STRIPPING WITH PULSE VOLTAMMETRY

This paper describes stripping pulse voltammetric methods of determination of midazolam, a benzodiazepine of clinical usage commercialized In the U.S. and Europe under the tradenames of Versed and Hypnovel and Dormlcum, respectively, using the adsorptive and electroactive properties of midazolam at the mercury electrode. Normal pulse and square wave voltammetries are suitable techniques for determination of midazolam In the micromolar range In quiet aqueous solutions at the stationary mercury electrode. The effect of uncompensated resistance on analytical results Is demonstrated. As an example, the determination of midazolam at the nanomolar level is presented using square wave stripping voltammetry. The optimum accumulation potential Is −0.6 V vs SCE. Accumulation times used are up to 4 min with magnetic stirring of the solution. The medium employed is acetate buffer pH ca. 4.8. The detection limits are on the order of 100 pM. © 1990, American Chemical Society. All rights reserved.