Potentiometric Determination of Chlorpromazine HCl Using Carbon Paste Electrode in Pure and Pharmaceutical Preparations

Carbon paste electrode has been developed for the potentiometric determination of chlorpromazine HCl drug. This work has focused on the fabrication of carbon paste ion selective electrode for determination of the drug under investigation using potentiometric titration with sodium tetraphenylborate. The performance of such sensor in the potentiometric determination of chlorpromazine HCl is compared with those of PVC membrane, coated wire and coated graphite electrodes. This carbon paste electrode was applied to the determination of chlorpromazine HCl in pharmaceutical preparations. The repeatability and accuracy of measurements performed in the analysis of these pharmaceutical matrices using new carbon paste sensor were evaluated. The influence of the electrode composition, conditioning time of the electrode and pH of the test solution, on the electrode performance were investigated. The drug electrode showed Nernstian response in the concentration range from 1x10(-7) to 1x10(-2) mol L-1 with slope of 58.06 +/- 0.34 mV decade(-1), and was found to be very precise and usable within the pH range 2-6. This sensor exhibited a low detection limit (1x10(-7) mol L-1), a long lifetime (>2 months) and good stability. The percentage recovery obtained is 97.72% with a relative standard deviation <= 0.28%.