MEASUREMENT OF BROMATE IN BOTTLED WATER BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH POSTCOLUMN FLOW REACTOR DETECTION

The objective of this work was to develop a reliable, rugged high-perf ormance liquid chromatographic (HPLC) method for determination of trac e levels of bromate (< 10 mu g/l) in bottled water. HPLC separation wa s achieved by ion interaction chromatography using a C-18 reversed-pha se column and a mobile phase consisting of methanol/water (20:80, v/v) with tetrabutylammonium acetate as the ion interaction reagent. A pos t-column reaction based on oxidation of o-dianisidine in acidic soluti on to a product detected at 500 nn provided selective measurement of t he oxidants. The limit of detection and the Limit of quantitation were 1 and 3 mu g/l, respectively. Iodate, chlorite, and nitrite were chro matographically separated from bromate and measured by monitoring the post-column reaction. Chloride and chlorate at levels that might be fo und in bottled water did not interfere with the determination of broma te. Bromate was detected in bottled waters at concentrations up to 40 mu g/l.