Determination of emodin,rhein,chrysophanol and rheochrysidin in Tongshukoushuang capsules by HPLC

Objective To develop an HPLC method for the determination of emodin,rhein,chrysophanol and rheoehrysidin in Tongshukoushuang capsules.Methods Diamonsil C18(200 mm ×4.6 mm,5 μm) column was used with the mobile phase of methanol-0.05% phosphoric acid solution(92∶8,v/v).The flow rate was 1.0 mL·min-1 and the column temperature was 30 ℃.The detection wave-length was 254 nm.Results The calibration curve was linear within 0.7～7.0 μg·mL-1(r=0.999 9),0.384～3.84 μg·mL-1(r= 0.999 6),1.803～18.03 μg·mL-1(r=0.999 7),and 0.504～5.04 μg·mL-1(r=0.999 9) for emodin,rhein,chrysophanol,and rheochrysidin,respectively.The average recoveries were 99.3%,100.7%,100.9% and 99.1% for emodin,rhein,chrysophanol,and rheochrysidin,respectively.Conclusion This method is convenient,accurate and reproducible for the determination of emodin,rhein,chrysophanol,and rheoehrysidin in Tongshukoushuang capsules.