Abstract: A method for determination of 23 kinds of phthalic ester in cosmetics simultaneously by UPLC-MS/MS was established.Various types of cosmetics were extracted and purified by different methods.MRM mode was used to qualitatively identify the 23 target compounds and isotope internal standards were used to quantify by calibration curves.In the range of 0.01－1.0 mg·L^-1,the linearity of the method is good and the correlation coefficients are over 0.998.The LOD of the method ranges within 0.003－0.095 μg·g^-1.The average recovery of the method ranges within 86.1%－100.5% (n=9) and the RSD ranges within 0.74%－3.23%.Methodology experiment displayed that the reproducibility,precision and stability of the method are good.

Key words: cosmetics, phthalic ester, UPLC-MS/MS, isotope internal standards