The use of nitrite ion in the chromatographic determination of large amounts of hypochlorite ion and of traces of chlorite and chlorate ions

Abstract

An ion chromatographic procedure was developed for the one-run determination of ClO^–, ClO₂^– and ClO₃^– present at very different concentration levels in the same sample. The method is based on the quantitative and fast reduction of HClO in slightly acidic medium by added sodium nitrite, followed by the ion chromatographic determination of ClO₂^–, ClO₃^– and the generated NO₃^–. The possibility of amperometric titration of the ‘free chlorine’ with a standard solution of NaNO₂ was also ascertained. The performance characteristics of the analysis were defined.