Abstract: A high performance liquid chromatography (HPLC) method for the determination of two optical isomers of arbutin (α-arbutin and β-arbutin) and niacinamide in cosmetics was developed. The samples were extracted by the mixture of salt water and chloroform (2:1, v/v). The separation was performed on an ODS-BP column (200 mm×4.6 mm, 5 μm, Elite) with methanol-water (10:90, v/v) as the mobile phase at a flow rate of 0.5 mL/min and 25 ℃. The detection wavelength was set at 220 nm and the sample injection volume was 20 μL. There were good linear relationships between the mass concentration and the peak areas of α-arbutin, β-arbutin and niacinamide in the ranges of 0.07~50, 0.06~50 and 0.05~50 mg/L, respectively. The relative standard deviations (RSDs, n=7) of α-arbutin, β-arbutin and niacinamide were 1.65%, 1.73% and 1.33%, respectively. The proposed method has been applied for the determination of α-arbutin, β-arbutin and niacinamide in cosmetics with recoveries of 91.7%~109.6%. This method is rapid, simple and suitable for the detection of whitening ingredients in cosmetic.

Key words: cosmetics , niacinamide, α-arbutin, β-arbutin, high performance liquid chromatography (HPLC)