Abstract:

A method for the determination of 2-（2-benzotriazolyl）-4-methylphenol（UV-P）, 2-benzotriazol-2-yl-4-（1, 1, 3, 3-tetramethylbutyl）phenol（UV-329）, 2-tert-butyl-6-（5-chloro-2H-benzotriazol-2-yl）-4-methylphenol（UV-326）, 2-（benzotriazol-2-yl）-4-methyl-6-[2-methyl-3-[methyl-bis（trimethylsilyloxy）silyl]propyl]phenol（DTTSO） and 2, 2-methylenebis[6-（2H-benzotriazol-2-yl）-4-（1, 1, 3, 3-tetramethylbutyl）phenol]（UV-360） in cosmetics by high performance liquid chromatography was established. Watery cosmetics were dissolved in methanol/tetrahydrofuran, ultrasonically extracted, and filtered by microporous membrane for injection. Emulsion and cream cosmetics were prepared by methanol/tetrahydrofuran dissolution, vortex oscillation, ultrasonic extraction, and microporous membrane filtration injection. The target chemicals were separated on ZORBAX SC-C18 column（250 mm×4.6 mm, 5 μm）using 0.1% formic acid, methanol and tetrahydrofuran as mobile phases and detected at 340 nm and 23 ℃. The flow rate of the mobile phase was 1.0 mL/min and the injection volume was 5 μL. The results show that the five benzotriazole ultraviolet absorbents have a good linear relationship in the mass concentration range of about 11-176 mg/L（R²≧0.999 4）, the detection limits are 6.72, 11.94, 13.80, 18.47 and 23.49 μg/L, respectively, the relative standard deviation is less than 1.7%（n=6）, and the average recovery rate is 93.7%-104.5%. The method is suitable for the determination of five benzotriazole ultraviolet absorbents in cosmetics.

Key words: ultrasonic extraction, high performance liquid chromatography, cosmetic, benzotriazole, sunscreen, ultraviolet absorbent