Nanoalumina Modified Carbon Paste Electrode for Sensitive and Rapid Determination of Hypochlorite Ion by Differential Pulse Voltammetry

An anodic stripping differential pulse voltammetric method was proposed for rapid and sensitive determination of hypochlorite (OCl-) ion. A modified electrode was prepared by modification of carbon paste using alumina nanopowder. This rapid, simple and accurate method is based on the electrooxidation of OCl- ion accumulated at the electrode surface. Nanoalumina modification increased the oxidation peak current for OCl- ion. The effects of different parameters on the electrode response were studied and the optimum condition was established. The response of the sensor was linear in the range 0.1-800 μg ml-1 of OCl- ion, with a correlation coefficient of 0.9992 at the optimum condition. The limit of detection was obtained as 0.025 μg ml-1. The effects of some cations, anions and organic species, which may coexist with OCl- ion in real samples on the current response of OCl-, were investigated. The investigated chemical species did not interfere with the OCl- electrochemical signal. OCl- ion in water and dairy product samples was successfully determined using the proposed electrode.