DETERMINATION OF BENZOYL PEROXIDE IN WHEAT-FLOUR BY ION CHROMATOGRAPHY WITH PRECOLUMN DERIVATIZATION

A novel method for the determination of benzoyl peroxide bleach in whe at flour by using high performance anion exchange chromatography (HPIC ) after decomposition to benzoic acid was proposed. Benzoyl peroxide w as effectively extracted from wheat flour with absolute ethanol by ult rasonication under neutral condition and converted to benzoic acid in the presence of potassium hydroxide solution. The chromatographic sepa ration of benzoic acid was performed on a Dionex OmniPac PAX-100 separ ation column and the determination by ultraviolet absorbance detection at 222 nm. Good linearity between the concentration of benzoyl peroxi de and peak area response nas achieved in the range of 0.12-20 mu g/mL . The detection limit (signal-to-noise ratio 3:1) was 19 ng/mL for ben zoyl peroxide. The method has been successfully applied for the analys is of real samples, and the average recoveries for various samples ran ged from 81 to 92%.