A Novel Simplified Column-Switching Technique for the Determination of Traces of Bromate in High Concentration Matrices

Abstract.

The column-switching technique has been widely used to determine trace level ions in the presence of high concentration matrix. A novel simplified column-switching method is proposed where bromate (as a model compound) was determined using this technique. The switching time window was confirmed by the retention time of determined ions. This technique can completely carry out the same function as the other column-switching technique do, but only one extra ten-way injection valve coupled to ion chromatograph was used. By using column-switching technique, it is possible to determine 0.2 µg L⁻¹ bromate in the presence of 100 mg L⁻¹ chloride by direct injection of 2000 µL without any pretreatment and the relative standard deviation (RSD) of the peak height for the eleven successive injections of 0.2 µg L⁻¹ bromate solution is 23.1%. The detection limit for bromate is 0.09 µg L⁻¹, which showed the method was very sensitive. The technique has been applied to the determination of bromate in drinking water, and the spike recovery is in the range of 96–104%.