A rapid and selective carbon composite platinum coated electrode for determination of copper ion in real samples

A Pt wire coated with pyridine-2,6-dicarboxamide derivative-carbon composite in a poly(vinyl chloride) membrane was used for detection of copper. The sensor has a Nernstian slope of 29.50 +/- 0.17 mV per decade over a wide range concentration, of 8.7 x 10(-7) to 1.0 x 10(-1) mol L-1 for Cu2+ ions. The detection limit is 1.1 x 10(-7) mol L-1 and the electrode is applicable in the pH range of 3.0-7.0. The response time of the proposed electrode is 6 s, its life time is at least 3 months and it has good selectivity. The practical analytical utility of the electrode is demonstrated by measurement of Cu2+ ions in multivitamin, orange juice, river water and as indicator electrode in potentiometric titration of copper ion with EDTA. From the obtained data it is seen that there is satisfactory agreement between the results obtain by the proposed electrode and those determined by atomic absorption spectroscopy (AAS), and perfect stoichiometry is observed in titration plot.