DETERMINATION OF SUNSCREEN COMPOUNDS IN TOPICAL SUNSCREEN PRODUCTS

A method for the determination of sunscreen compounds in over-the-counter topical sunscreen products is described. The method uses reversed-phase liquid chromatography with an eluent of tetrahydrofuran and dilute acetic acid. The analytes are detected using an ultraviolet detector at 313 nm. The selectivity of methanol, acetonitrile, and tetrahydrofuran was investigated using selected test sunscreen compounds. The best selectivity for the separation of the analytes was obtained using tetrahydrofuran. The specificity of the method was demonstrated by showing that the analytes could be separated from several potential degradation products. Quantitative recoveries were obtained for all six sunscreen compounds determined in a variety of formulations. © 1990.