Differential Pulse Voltammetric Determination of Free Chlorine for Water Disinfection Process

The electrochemical detection of free chlorine based on the reduction at a gold electrode has been studied. The dif- ferential pulse voltammetric curves exhibited well-defined cathodic peaks. Investigations with this system suggested that the active species in the cathodic reaction is HClO. Excellent reproducibility was demonstrated at pH 5. The peak height could be used for accurate and rapid determination of free chlorine in a sample water. A linear rela- tionship (r 2 =0.99) was found for the concentration range of 1–5 mgCldm�3 and the detection limit was estimated to be 0.04 mgCldm�3 . Keywords: Differential pulse voltammetry, Free chlorine, HClO reduction, Gold electrode, Drinking wate