Abstract:

A high performance liquid chromatography （HPLC）-diode array detector （DAD） method was established for the simultaneous determination of 5 kinds of prohibited phenols in cosmetics, including 2, 4, 6-trinitrophenol, 2, 4, 6-trichlorophenol, sesamol, dinoseb, and phloroglucinol. The sample was extracted with methanol in ultrasonic assisted extraction coupled with high speed centrifugation. The separation was performed on Eclipse XDB-C₁₈ column （250 mm×4.6 mm, 5 μm） using gradient elution with acetonitrile/0.1% （V/V） phosphoric acid solution as the mobile phase, and the content was quantified by external standard method. The results show that 2, 4, 6-trinitrophenol has a good linear relationship in the range of 0.125-5.0 μg/mL with the correlation coefficient higher than 0.999 9, and the other 4 prohibited phenols have good linear relationships in the range of 0.25-10.0 μg/mL with the correlation coefficients all higher than 0.999 8. The limits of detection （LOD） and quantitation （LOQ） of the five phenols are 4-8 mg/kg and 10-20 mg/kg, respectively. The recoveries of 5 kinds of prohibited phenols are ranged from 91.3% to 104%, with the relative standard deviations （RSDs） of 0.4% to 5.1% in water-based, emulsion, cream and powder cosmetics under the three levels of low, medium and high, respectively. The simple-pretreatment, rapid, accurate, high sensitivity method can be used for providing technical support for the accurate quantification of prohibited phenols in cosmetics.

Key words: high performance liquid chromatography （HPLC）, cosmetics, prohibited phenols, sesamol, 2, 4, 6-trinitrophenol, 2, 4, 6-trichlorophenol