Determination of benzoyl peroxide in anti-acne cosmetics by static injection chemiluminescence

The rapid and easy static injection chemiluminescence method was established to measure the content of benzoyl peroxide(BPO) in the cosmetics.Based on the fact that the BPO can directly react with Luminol to produce chemiluminescence in the presence of Co2+ as the catalyst in an alkaline solution,and various factors influencing the chemiluminescence system were investigated carefully.The possible mechanism of the proposed method was also studied preliminarily.The results showed that 1.25×10-4mol/L Luminol,Na2CO3-NaHCO3 buffer solution of 2.5×10-4mol/L and 5×10-7g/L Co2+ was the chemical composition of the optimal chemiluminescence system.The detection limit is 3.0×10-9 g/mL,the linear range of the determination was from 1.0×10-8 ~1.0×10-6 g/mL and r=0.9967,the relative standard deviation was 2.0%(5.0×10-8 g/mL,n=11).This method is proved to be of high sensitivity,low detection limit,simple operation and inexpensive devices.The recommended method has been successfully used for the analysis of BPO in anti-acne cosmetics.