Coated Wire PVC Membrane Sensor for Selective Determination of Copper Ion in Environmental Samples and Pharmaceutical Formulations

Nashwa      M. H. Rizk

Abstract

This work described the electrochemical response characteristic of poly (vinyl chloride) (PVC) membrane sensor and coated wire ion selective electrode (CWISE) based on the use of copper (II) salicylidene-N – anilinoacetohydrazone ionophore. o-nitrophenyloctylether (o-NPOE) is used as a plasticizer in the PVC matrix. The membrane sensors were prepared and the performance characteristics were evaluated according to IUPAC recommendations. The prepared sensors exhibited fast, stable and linear response for copper over a concentration range 1× 10× 6-1× 10× 2 M and 7× 10-5- 1× 10-2 M with cationic slopes of 29.6 and 27.1 mV per concentration decade at pH 5 for membranes doped with and without tetraphenylborate as an additive, respectively. The potentiometric selectivity data revealed minimal or no interference from common cations. Direct potentiometric determination of copper using the prepared membrane sensors gave average recoveries of 99.89 ± 0.9% and 100.04 ± 1.1% for membrane formulated with additive (detection limit; 1× 10-6-1× 10-2 M) and without additive (detection limit; 7× 10-5-1× 10-2 M), respectively. The sensors were used for measurement of copper content in industrial waste water; metal alloys containing from copper factories and pharmaceutical formulations. The developed method was found to be simple, accurate and precise when compared with conventional analytical methods for copper determinations (e.g; atomic absorption spectroscopy and voltammetry).

Keywords: Salicylidene-N -anilinoacetohydrazone, Coated wire, Copper, Potentiometry, Waste water, Pharmaceutical formulations, Environmental Samples, Ion selective electrode, Spectrophotometry, Voltammetry, stripping potentiometry