Inorganic Oxyhalide By-Products in Drinking Water and Ion Chromatographic Determination Methods

Many drinking water utilities are changing their primary disinfectant from chlorine to alternative dis-infectants such as ozone, chlorine dioxide and chloramines, which reduce regulated trihalomethanes and some organochlorine compounds levels, but often increase levels of others potentially toxicologically im-portant compounds. The hazardous inorganic oxyhalide by-products are bromate, chlorite and chlorate, some of which have been classified as probable human carcinogens. The most important of these is bro-mate, formed when source waters containing bromide are ozonated. Chlorite is formed when chlorine di-oxide is used, whereas chlorate is formed when chlorine, chlorine dioxide, hypochlorite acid or chloramine is used to disinfect drinking water. This paper is a review of ion chromatographic separations of these inorganic oxyhalide disinfection by-products in drinking water and their detection using conductivity, UV/Vis or mass spectrometry detection. The critical comparison of ISO, US EPA and other methods including limits of detection, availability and costs of analyses is given. Furthermore, a review of papers concerning ion chromatography determination of inorganic oxyhalides in drinking water published during the last 20 years is presented.