Quantitative analysis of trace level bromate and chlorate ions in drinking water by ion chromatography

Quantitative analysis of bromate and chlorate ions contaminated in bottled drinking water were determined by ion chromatographic technique. Prior to analysis, samples were preconcentrated by heating to reduce volume of sample by 5 times, and silver nitrate solution was added to remove chloride ions interference. Separation was performed on STAR-ION-A300 column using a buffer solution of NaHCO3 and Na2CO3 with concentration ratio of 2.2:5.0 mM as mobile phase at flow rate of 1.0 ml/min. The experimental results showed that linearity of calibration curves for quantitative analysis of bromate and chlorate ions were in the concentration range of 0.003-9.0 ppm with R sup (2) of 0.999. The limit of detection (LOD) of bromate and chlorate ion were 0.003 and 0.002 ppm respectively. The precision in term of percentage relative standard deviation (percent RSD) and the accuracy in term of percentage recoveries of this method were in range of 1.28-2.52 percent and 96.6-98.1 percent respectively. Therefore, sample preconcentration by simple heating for volume reduction was an appropriate sample preparation step for trace analysis of bromate and chlorate ions by ion chromatography, and the method was simple with high accuracy and precision .