SIMULTANEOUS DETERMINATION OF CHLORINE DIOXIDE AND HYPOCHLORITE IN WATER BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The simultaneous determination of chlorine dioxide and hypochlorite by high-performance liquid chromatography was developed. The chromogenic substance formed by the oxidation-condensation reaction using 4-amino antipyrine (4-AA) and phenol was determined at 503 nm by a post-column reaction system. Chlorine dioxide and hypochlorite were separated wit hin 3 min by applying the elution solution (1.7 mM sodium carbonate-1. 8 mM sodium carbonate) at 0.5 mi/min into a laboratory-prepared PTFE t ube column (13 cmx1.0 mm I.D.x2 mm O.D.) packed with Waters Accell QMA as the anion-exchange material. A linear correlation between the peak height and concentration was obtained within the range of 1-20 mu g/m l for chlorine dioxide and 47-200 mu g/ml for hypochlorite, with good reproducibility (relative standard deviations of 4.0 and 2.2%, respect ively, replicated determination). The limits of detection of chlorine dioxide and hypochlorite were approximately 0.2 and 10 mu g/ml (SIN=3) , respectively. (C) 1998 Elsevier Science B.V.