[Determination of benzoyl peroxide in wheat flour by micellar capillary electrophoresis on-line sweeping...

A method for the determination of benzoyl peroxide in wheat flour was established by a micellar capillary electrophoresis on-line sweeping concentration technique. Benzoyl peroxide was ultrasonically extracted with methanol, filtrated by nylon membrane (0.45 microm), and analyzed directly by capillary electrophoresis. The conditions of pH of background solution, the concentration of sodium dodecyl sulfate (SDS) and injection time were investigated. The results demonstrated that the optimum separation efficiency can be obtained by using a running buffer of 0.02 mol/L borax-boric acid containing 0.04 mol/L SDS (pH 9.0), UV detection at a wavelength of 214 nm and an applied voltage of 10 kV. These conditions allowed up to 150-fold concentration of benzoyl peroxide and a linear correlation of benzoyl peroxide was obtained in a range from 0.002 g/L to 0.012 g/L. The detection limit was 2 mg/L. The results also showed that the method is precise, simple, and cost-effective.