Electroanalytical Determination of Cadmium and Lead using Edge Plane Prolytic Graphite/Polyaniline Electrode

Abstract

In this work edge plane pyrolytic graphite electrode substrate electropolymerized with polyaniline thin film via multipulse cyclic voltammetry to form edge plane pyrolytic graphite/polyaniline (PG/PANI) electrode was successfully used for simultaneous determination of Cd²⁺ and Pb²⁺ ions. Anodic-stripping square wave voltammetric (AS-SWV) technique was used for this sensor development. The results reported indicate that modifying the edge plane pyrolytic graphite electrode with polyaniline increases the detection signals for Cd²⁺ and Pb²⁺ by 1.6 and 2.5 times respectively. Among the variables optimized were: deposition time (60 sec), deposition potential (0.05 V), amplitude (0.02 V) and frequency (35 Hz) for Cd²⁺ and deposition time (60 sec), deposition potential (0.05 V), amplitude (0.02 V) and frequency (25 Hz) for Pb²⁺. The limits of detection, limits of quantitation and linear ranges were found to be 0.11ppm, 0.37ppm and 0.10ppm – 0.50ppm for Pb²⁺ and 0.908ppm, 3.03ppm and 1.0ppm – 5.0ppm for Cd²⁺ respectively. This proposed electroanalytical method uses non-mercury based electrodes. Its also simple and cheaper compared to other alternatives such as carbon nanotube electrode arrays.