Determination of benzoic acid and potassium bromate in wheat flour and flour products by ion chromatography(IC) with suppressed conductivity

Object:Ion chromatography method for simultaneously determining benzoic acid and potassium bromate in wheat flour and flour products was developed.Methods:Bromate was first extracted from the sample with water and purified by solid phase extraction on a silver column,then determined by ion chromatography.Chromatographic separation was carried out on IonPac AS23 column with ASRS4mm suppressor,and a suppressed conductivity detector was used to the determination.Results:Benzoic acid was linear in the range 5～90 μg/mL and the linear correlation coefficient reached 0.9993.Bromate was linear in the range 1～50 μg/mL and the linear correlation coefficient reached 0.9965.The recoveries at the spiked levels of benzoic acid were 86.1%~96.5%.The recoveries at the spiked levels of bromate were 92.2%~103.3%.Conclusion:The method is reliable,sensitive,high recovery and adapts to the determination of benzoyl peroxide and potassium bromate in wheat flour and flour products.