Determination of Trace Concentrations of Oxyhalides and Bromide in Municipal and Bottled Waters Using a Hydroxide-Selective Column with a Reagent-Free Ion Chromatography System

INTRODUCTION All drinking water municipalities share the same goal of providing their communities with a reliable source of safe drinking water. To achieve this goal, most water systems must treat their water. The type of treatment used varies depending on the size, source, and water quality. Disinfection protects public water systems (PWSs) from potentially dangerous microbes. The most common chemical disinfectants are chlorine, chlorine dioxide, chloramine, and ozone. These chemical disinfectants can react with natural organic and inorganic matter in the source water to produce disinfection by-products (DBPs) that are potentially harmful to humans. For example, chlorination of drinking water can produce trihalomethanes, haloacetic acids, and chlorate. While chlorine dioxide treatment generates the inorganic oxyhalide DBPs chlorite and chlorate, and the presence of chloramine has also been known to generate chlorate. Ozone reacts with naturally occurring bromide to produce bromate. The International Agency for Research on Cancer has identified bromate as an animal carcinogen and potential human carcinogen. The World Health Organization (WHO) has estimated an excess lifetime cancer risk of 10 for drinking water containing bromate at 3 μg/L.