Authors: Sayed A M Marzouk Wadie T AlAriqui Saad S M Hassan
Publish Date: 2003/02/28
Volume: 375, Issue: 8, Pages: 1186-1192
Abstract
Preparation characterization and applications of a 110phenanthrolinium cation phenH+sensitive potentiometric sensor are described The sensor incorporates a liquid polymeric membrane consisting of phenHtetraphenylborate nitrophenyloctyl ether and polyvinyl chloride as ion exchanger plasticizer and polymeric support respectively The sensor exhibits a fast and Nernstian response to phenH+ over the concentration range of 6×10−6–2×10−4 M with a monovalent cationic slope of 580±05 mV/logphenH+ in acetate buffer of pH 42 The sensor is successfully applied to the monitoring of the potentiometric titration of HgII and CuII ions with phen solution in the presence of citrate and acetate buffers of pH 42 respectively Sharp inflection breaks 90–180 mV at 11 metalphen reaction are obtained in the presence of chloride and thiocyanate background This stoichiometry is explained by the formation of insoluble HgCl2phen HgSCN2phen and CuSCN2phen complexes Optimization of each titration and the effect of foreign ions are evaluated The method offers the advantages of adequate sensitivity accuracy and selectivity for the determination of mercury and copper in pharmaceutical rock and tea samples The results are in good agreement with those obtained using the standard atomic absorption spectrometric and United States Pharmacopeial methods
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