[High performance liquid chromatographic analysis of typical ultraviolet absorbers in cosmetic products]

Typical 11 ultraviolet (UV) absorbers in cosmetic products were separated and determined by high performance liquid chromatography. The recommended conditions for the analysis were as follows: column, 4.6 mm i.d. x 250 mm, Capcell Pak C18 SG (5 microns); detector, UV spectrophotometer (280 nm); column temperature, 40 degrees C; mobile phase, H2O-CH3OH (15:85 v/v) containing 3 mM stearyltrimethyl ammonium chloride; flow rate, 1.0 ml/min. In the case of the products containing 2-ethylhexyl p-methoxycinnamate (OMC) and/or 4-tert-butyl-4'-methoxydibenzoylmethane (BMD), it was necessary to use H2O-1,4-dioxane (34:66 v/v) containing 6 mM stearyltrimethyl ammonium chloride as the mobile phase in order to separate OMC and BMD. Anthracene and 9,10-dimethylanthracene were used as an internal standard for the H2O-CH3OH mobile phase and the H2O-1,4-dioxane mobile phase, respectively. Calibration curves were linear within a range of 50-150 micrograms/ml for the 11 UV absorbers. Recoveries and reproducibilities of the method were satisfactory. By using this method, typical UV absorbers in several commercial cosmetic products such as lip creams, sun oils, lotions and emulsions were able to be rapidly determined without any interference.