Determination of taurine in cosmetics by HPLC with pre-column derivatization

Based on different formula structures, a method was established for the determination of taurine in cosmetics with 2,4-dinitrofluorobenzene as pre-column derivate reagent by high performance liquid chromatography (HPLC). Water-soluble cosmetics and oil-in-water cosmetics were diluted with water, ultrasonic extraction, centrifugal filtration and then directly derived and determined by HPLC; water-in-oil cosmetics were pre-dispersed with acetonitrile, diluted with water,ultrasonic extraction, centrifugal filtration, then derivatized and determined by HPLC. The methods were optimized in terms of the selection and addition amount of derivatization reagents, the possible interferences of the matrix, and the selection and addition amount of pre-dispersing solvents. The derivatives were separated using an Ultimate Amino Acid (4. 6 mm ×250 mm, 5 μm) chromatographic column, and the mobile phases for gradient elution with 50 mmol L sodium acetate-acetonitrile (1∶1, V V) and 50 mmol/ L sodium acetate aqueous solution. The column temperature was 32℃, the flow rate was 1. 0 mL/ min, the detection wavelength was 355 nm, and the injection volume was 20 μL. Quantification was performed using external standards. Good linearity was obtained in the concentration range of 5. 0 -100 mg/ L with correlation coefficient of 0. 994, the limit of detection(LOD) was 6 mg/ kg, and the limit of quantification (LOQ) was 20 mg kg. The average recoveries of the target at the three levels were in the range of 95. 6% -103. 7% with the relative standard deviations (RSDs) within 1. 1% -4. 4%. The results showed that the analysis method meet the requirements for efficient analysis of taurine in cosmetics. © 2021, Youke Publishing Co.,Ltd. All rights reserved.