Application of ion-chromatography for the determination of the organic-group parameters AOCl, AOBr and AOI in water

Abstract A method of differential AOX-analysis, i.e. the simultaneous determination of AOCl, AOBr and AOI is described. Individual steps of the method including enrichment at activated carbon, combustion in an oxygen stream and ion-chromatographic detection were optimized. In most cases quantitative recoveries of various organic Cl, Br and I containing substances of different polarity and structure were obtained. The method was applied to the determination of AOX-fractions in municipal and hospital wastewater. A good agreement between conventional coulometric and the described ion-chromatographic determination was found. High concentrations up to 130 μg/L I of organic iodine compounds were measured in the influent and effluent of a municipal treatment plant in Berlin and up to 10 mg/L I in a hospital wastewater.