Study on Spectrophotometric Determination of Potassium Bromate by Oxidation-Decoloration of AlizarinViolet

Using the oxidation-decoloration of alizarin violet by potassium bromate in hydrochloric acid medium,the appropriate conditions were studied and a new method for the determination of the trace potassium bromate was established.The experimental results showed that the maximum absorption peak is located at 460 nm with an apparent molar absorption coefficient of 1.9×104L·mol-1·cm-1.The linear range is 1~20mg·L-1,the recovery was from 95% to 103%,relative standard deviation was 2.3%;detection limit was 1.02 mg·L-1.The proposed method has been applied in determining of trace potassium bromate in food sample with satisfactory results.