[Analytical application of phosphotungstic acid complexes. Fabrication and characterisation of membrane selective electrodes for some H2 antihistaminics].

PVC matrix membrane selective electrodes for ranitidine, nizatidine and famotidine, based on sparingly soluble complexes, were prepared and characterized. The optimum functional pH range, response time, selectivity and lifetime were determined for each of the built electrodes. The linear range, precision and accuracy of each method were obtained by statistical interpretation of experimental results, while the limit of detection and thelimit of quantification were determined by a graphical method. All these electrodes were applied for the direct quantitative potentiometric determination of ranitidine hydrochloride, nizatidine and famotidine in pharmaceutical formulations.