Abstract: A high performance liquid chromatography was used to determine the content of tranexamic acid in cosmetics.The Zorbax SB C₁₈ chromatographic column (250 mm×4.6 mm,5 μm) was used for separation,and water-methanol-18.3 g/L sodium dihydrogen phosphate solution (containing volume fraction 1.26% triethylamine and adjusted pH to 2.5 by phosphoric acid) was used as mobile phase for gradient elution,with a flow rate of 0.8 mL/min.Temperature of the column was 25 ℃ and the injection volume was 10 μL.Samples were extracted with methanol/saturated sodium chloride solution (volume ratio of 1∶1) and quantitated by diode array detector at 220 nm with external standard method.Results show that tranexamic acid has a good linear relationship in the range of 100-4 000 mg/L,and the correlation coefficient (R²) is 0.999 9.Limit of detection and quantitation of the method are 7 and 22 mg/L separately.The average spiked recoveries vary from 94.0% to 102.5%,and the relative standard deviations achieve 0.57%-2.69% (n=3).This method has the advantages of simple pretreatment,high recovery and good precision for the determination of the content of tranexamic acid in cosmetics.

Key words: additive of cosmetics, high performance liquid chromatography, tranexamic acid