[Determination of benzoyl peroxide in wheat flour by high performance liquid chromatography]

An improved method for the determination of benzoyl peroxide in wheat flour is reported. Benzoyl peroxide was extracted with petroleum ether, and then analysed by reversed-phase high performance liquid chromatography on a Shim-Pack VP-ODS column (0.46 cm i.d. x 15 cm, 5 microm - 6 microm) using a mobile phase of acetonitrile-0.3% H3PO4 aqueous solution (4:1 in volume ratio) with a flow rate of 1.0 mL/min, and UV-236 nm detection. A linear correlation was observed between 0.002 g/L- 0.012 g/L of benzoyl peroxide. The detection limit was 0.005 g/kg. This proposed method without redox reaction is superior to colorimetric determination. This method is characterized with simplicity, convenience, reproducibility and accuracy.