New potentiometric sensor for the determination of bromate ion in drinking water

The characteristics, performance and application of ion-selective electrodes for bromate ion based on rhodamine B and tetrahexyl ammonium bromide as electrode-active substances are described for the first time. These electrodes respond with sensitivities of (58.0±1.0) and (61.0±2.0) mV decade−1 over the range 1.0×10−8–1.0×10−2 mol l−1 at pH 4–9 and 4–8 and a detection limit of 6.0×10−8 and 4.0×10−8 mol l−1 for rhodamine B and tetrahexyl ammonium bromide sensors, respectively. The electrodes are easily constructed at a relatively low cost, have a fast response time and can be used for a period of 3 months without any considerable divergence in potential. The proposed sensors displayed good selectivity for bromate ion in the presence of several substances and inorganic anions. Sensors were used for the direct assay of bromate ion in drinking water samples.