Determination of Diethylstilbestrol in Cosmetics by High Speed Liquid Chromatography

Abstract

A method was described for the quantitative determination of diethylstilbestrol (DES) in cosmetics. The DES was extracted from samples with dichloromethane, the extract was evaporated, the residue was placed on a silicagel column, and the column was washed with benzene to remove impurities. DES was eluted from the silicagel column with ethyl acetate and determined by high-speed liquid chromatography on a zorbax SIL column, by using ethanol-hexane as eluting solvent and a 240 nm UV monitor for detection. A calibration curve showed linearity in the range of 0.05-0.5 μg of DES, and the detection limit was 0.01 μg. Average recoveries of 100 μg DES added to 5 g samples of skin cream and hair tonic were 90.6 % and 92.1 %, respectively.