Differential Pulse Anodic Stripping Voltammetric Determination of Cadmium(II) at a Glassy Carbon Electrode Modified with a Nano-TiO2/Chitosan Composite Film

A simple and effective chemically modified electrode for the determination of cadmium(II) was developed. The chemically modified electrode was prepared by modifying nano-TiO2/chitosan (nano-TiO2/CS) composite film onto a glassy carbon (GC) electrode. Compared with a bare GC electrode and a CS film-modified GC electrode, the nano-TiO2/CS composite film-coated GC electrode significantly improved the sensitivity of determining Cd-II. The effects of experimental parameters such as modifier composition in the GC electrode, pH of supporting electrolyte, accumulation potential and time were studied for analytical application. Under the optimized working conditions, the peak currents were linear with concentration over the range from 1.0 x 10(-9) to 1.0 x 10(-6) mol L-1 for Cd-II. The limit of detection is 2.0 x 10(-10) mol L-1 Cd-II for 180-s accumulation. The application for the assay of trace levels of Cd-II in real water samples indicates that it is an economical and potent method.