Application of Electro-oxidation to the Detection of Hydrolyzed Chlorine in Aqueous Solution

Abstract

A detection method of low hydrolyzed-chlorine concentrations in chlorinated water using an electro-oxidation reaction has been studied at a platinum electrode. Owing the potential sweep measurement, the formation current of a Pt surface oxide was observed in the background solution; and interestingly, the current decreased with an increase in the hydrolyzed chlorine. The current-potential curves at various concentrations showed good reproducibility. Plots of the concentration vs. the current at fixed potentials showed a linear relationship with a negative slope. Moreover, potential-step chronocoulometry was successfully applied, and plots at a fixed time showed a good linear relationship in the low concentration range of 0.1∼1.0 mg dm⁻³. Based on these results, this technique can be used for the detection of low concentrations of hydrolyzed chlorine for practical purposes.