Determination of Polysilicone-15 and Other Six Kinds of Fat-soluble Sunscreen in Cosmetics by Ultra-High Performance Liquid Chromatography
An ultra-high performance liquid chromatography method was developed for the determination of 7 kinds of fat-soluble sunscreen agents containing polysilicone-15.The samples were ultrasonic extracted by ethanol-tetrahydrofuan(3∶1,V/V)mixed solution for determination.The determination was performed by gradient elution with isopropanol-tetrahydrofuran(90∶10,V/V)-water as the mobile phase on a Waters Symmetry C18(4.6×150 mm,3.5 μm)analytical column.The flow rate was 0.7 mL/min,the column temperature was 25 ℃,and the wavelength was 311 nm.The developed method showed good linear relationships,with correlation coefficients(r)of no less than 0.9999 in corresponding concentration ranges.The average spiked recoveriers of different substrates at three levels ranged from 94.4%to 103.0%,with the relative standard deviations(RSDs)ranging from 0.4%to 4.4%.The limits of detection were between 0.002%and 0.009%,and the limits of quantification ranged from 0.005%to 0.03%.Moeroever,all the analytes were stable within 48h.By applying the developed method to 30 cosmetic samples obtained from the Chinese market,the extraction efficiency of fat-soluble sunscreen agemts such as methylene bis-benzotriazolyl tetramethylbutylphenol and bis-ethylhexyloxyphenol methoxyphenyl triazine were greatly improved comparing with current method in Technical Specification for Safety of Cosmetics(2015 edition).The method is accurate,rapid,sensitive and stable,which is suitable for the determination of fat-soluble sunscreens in cosmetics.