Photometric redox determination of bromate ions in drinking water

A procedure is developed for the selective photometric redox determination of bromate ions in drinking waters of different types. Methylene Blue (MB), Variamine Blue (VB) and Safranin T (SAF) are studied as irreversibly oxidized redox indicators. The limits of detection for bromate ions are 0.4 and 1 μg/L for MB (VB) and SAF, respectively. Using MB as an indicator at the concentration of bromate ions 1 μg/L, the acceptable mass ratios of concomitant ions are as follows: IO3−, NO2− (1: 60); ClO−, ClO2− (1: 100); ClO3−, ClO4− IO4−, Br− I− (1: 200). In the concentration range of bromate ions 1–10 μg/L, the total determination error is 5–7%.