A Novel Clomipramine and Paroxetine-Selective Membrane Sensors and their Applications in Pharmaceutical Analysis

Selective electrodes based on the reineckate drugs ion pairs in a polyvinyl chloride(pvc) matrix membrane is proposed for the determination of clomipramine (clo) andparoxetine (prx) hydrochlorides. the ion-pair complexes of drug cations with reineckateanion are either dissolved in tetrahydrofuran solvent or dispersed in a pvc matrix, withdioctylphthalate or dioctyl sebacat plasticizers, and used as the ion-exchange membranes.the electrochemical response characteristics of electrodes incorporating these types ofmembranes are evaluated with regard to the effect of ph, foreign basic compounds, effect ofsoaking time and lifespan. a well defined internal electrode potential was achieved usingag/agcl disc in contact with the ion-pair electroactive membrane phase. the electrodesdisplay a stable fast nernstian response in the concentration ranges 10-2-10-7 mol l-1 for thetwo drug cations over the ph range 2-5, a short static response time less than 60 s andresponse remain stable for at least 6 weeks. the lower limit of detection was 10-7 mol l-1 forboth drugs. determination of as low as 8 ?g ml-1 of drugs hydrochloride shows an averagerecovery of 98.75 and 100.6% and a mean standard deviation of 0.70 and 0.35 for clo andprx drugs, respectively. selectivity coefficients for clo and prx drugs relative to anumbers of potential interfering substances were investigated. the electrodes exhibit usefulanalytical characteristics for determining clo and prx in some illicit powders. the resultsagree fairly well with those obtained by gas-liquid chromatography. the proposed electrodesare simple easy to construct and behave as symmetric ion selective electrodes (ises).