Simultaneous determination of five marker constituents in Ssanghwa tang by HPLC/DAD

A HPLC-DAD method was established for the simultaneous evaluation of five bioactive compounds in Ssanghwa tang (SHT) including glycyrrhizin, paeoniflorin, cinnamic acid, decursin and 6-gingerol. These compounds were separated in less than 40 min using a Dionex C(18) column with a gradient elution system of water and methanol at a flow rate of 1 ml/min. Calibration curve of standard components presented excellent linear regression (R(2) > 0.9903) within the test range. Limit of detection and limit of quantification varied from 0.07 to 0.46 mug/ml and 0.13 to 1.11 mug/ml, respectively. The relative standard deviations (RSDs) of data of the intraday and interday experiments were less than 3.67 and 5.73%, respectively. The accuracy of recovery test ranged from 95.98 to 105.88% with RSD values 0.10- 4.82%.