Determination of emodin and rhein in Niuhuangjiedu Tablets by HPLC / 中成药

Objective: A HPLC method for determination of emodin and rhein in Niuhuangjiedu Tablets was established. Methods: The chromatographic conditions were listed below: Diamonisil ODS C 18 column, UV detector at 254nm of wavelength, a mobile phase of methanol water phosphate acid(720∶280∶1),and 1mL?min -1 of flow rate. The retention time of emodin was 8.49 min and that of rhein was 15.56min. Results: The calibration curves were linear for emodin within 0.469～1.407?g( r =0.9992) and for rhein within 0.3125～ 0.9375?g ( r = 0.9992). The recoveries were 98.2%( RSD =0.43%)for emodin and 98.4%( RSD =0.72%)for rhein, respectively. Conclusion: This method is simple and the separate result is satisfactory.