UHPLC Determination of Diethyl Maleate in Cosmetics

UHPLC was applied to the determination of diethyl maleate in cosmetics. The sample was ultrasonically extracted with acetonitrile and separated by gradient elution with mixtures of acetonitrile and water mixed in various ratios on Waters ACQUITY UPLC HSS T3 column (100 mm×2.1 mm, 1.8 μm). The content of diethyl maleate was determined at the wavelength 220 nm with DAD. Linear relationship between values of peak area and mass concentration of diethyl maleate was kept in the range of 0.50-20 mg·L-1 with lower limit of determination (10S/N) of 0.5 mg·kg-1. Recovery and precision were tested by adding dethyl maleate standard solution to a same cosmetic sample at 2 concentrations, for 7 determinations, values of av. recovery found were 90.4% and 105%, and values of RSD′s found were 1.5% and 3.2% respectively.