Determination of free chlorine based on anodic voltammetry using platinum, gold, and glassy carbon electrodes

The oxidation of free chlorine on platinum, gold, and glassy carbon disk electrodes has been investigated by using anodic voltammetry to determine the free-chlorine concentration. The voltammetric curves exhibited well-defined anodic peaks. The influences of pH, free-chlorine concentration, and potential sweep rate on the electrode response were investigated. The results show that the measurement of the oxidation peak current can be used as the basis for a simple, accurate, and rapid method for the determination of ClO−, within a concentration range of 4-400 mg Cl l−1. The results of this method were in good agreement with those obtained by iodometric titration. Differential pulse voltammetry has also been examined, resulting in an improved sensitivity at a concentration of 1.0 mg Cl l−1.