RESUMO
OBJECTIVE:To establish amethod for simultaneous determination ofbenzoic acid,methylis salicylas and thymol in Compound thymol solution.METHODS:HPLC was performed on the column of Thermo Hypersil BDS C18 with the mobile phase ofacetonitrile-water-acetic acid(40∶60∶0.02,V/V/V)at a flow rate of 1 ml/min,the detection wavelength was 275 nm,column tem-perature was 30 ℃,and injection volume was 10 μl. RESULTS:The linear range was 0.045 2-0.9030 mg/ml for benzoic acid, 0.0492-0.9844 mg/ml for methylis salicylas and 0.046 4-0.927 0 mg/ml for thymol;RSDs of precision,stability and reproducibility tests were lower than 2%;recoveries were 98.40%-108.88%(RSD=3.26%,n=9),98.21%-104.07%(RSD=1.87%,n=9) and 96.83-107.09%(RSD=3.33%,n=9),respectively. CONCLUSIONS:The method is simple,accurate and specific,and accurately de-termine the contents of benzoic acid,methylis salicylas and thymol in Compound thymol solution.