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.
