HPLC Determination of Phthalates in Cosmetics

HPLC was applied to the determination of phthalates,including dimethyl phthalate (DMP),diethyl phthalate (DEP),dibutyl phthalate (DBP),dihexyl phthalate (DHP),and dioctyl phthalate (DOP) in cosmetics. The sample was ultrasonically extracted with methanol and centrifuged at high speed. The supernatant liquid obtained was filtrated with 0.45 μm membrane,and was separated by gradient elution with methanol and water on SB-C18 ZORBAX column (4.6 mm×150 mm,5 μm). The contents of phthalates were determined at the wavelength 230 nm by external standard method. Linear relationships between the values of peak area and mass concentration of 5 phthalates were kept in the range of 1-100 mg·L-1,with detection limits (3S/N) of 4.0,7.4,4.3,5.2,and 7.3 ng,respectively. The values of recovery found by standard addition method were in the range of 94.7%-101.1%,with RSD′s (n=6) ranged from 0.023% to 0.68%.