NEW, SENSITIVE AND SELECTIVE METHOD FOR DETERMINING SUB-MU-G L LEVELSOF BROMATE IN DRINKING-WATER/

Health effects studies suggest that bromate should be regulated at 0.5 mu g/l or less in drinking water. Accordingly, an analytical method i s needed to quantify this contaminant with great sensitivity and selec tivity. Past efforts to do this have focused on pre-concentration ion chromatographic (IC) separation followed by suppressed conductivity de tection. Interfering chloride was removed by passing samples over a si lver resin which increased sample analysis time to almost 1 h. Tn this paper, a new method which uses IC separation with no pre-treatment fo llowed by a post-column reaction to produce tribromide (Br-3(-)) from bromate, is applied to the analysis of a variety of aqueous samples. T he tribromide ion is detected by UV absorbance at 267 nm. This method is very sensitive for bromate with a limit of quantitation of 0.2 mu g /l and is also very selective. Common anions typically separated by IC exhibit no interference, even at the levels normally found in drinkin g water. (C) 1998 Elsevier Science B.V.