Simultaneous determination of ginsenosides and epimedium flavonoids in rat urine by HPLC-UV-ELSD

OBJECTIVE: To develop and validate a HPLC-UV-ELSD method for the simultaneous determination of ginsenosides and epimedium flavonoids in rat urine after intravenous administration of Jiweiling freeze-dried powder. METHOD: Chromatographic separation was performed on a C18 HPLC column, with gradient elution of acetonitrile and water as mobile phase. An UV detector was used at detection wavelength of 220 nm. An evaporative light scattering detector (ELSD) was used at drift tube temperature of 80 degrees C and gas pressure of 172.4 kPa. RESULT: The calibration curves were linear over the investigated concentration ranges with all correlation coefficients higher than 0.998. The a intra- and inter-day RSD were less than 9.1% and the relative errors were verage extraction recoveries for all compounds were between 88.67% and 101.2%. The within the range of -11.58% to 10.89%. CONCLUSION: The proposed method showed appropriate accuracy and selectivity and was successfully applied to the rat urine samples analysis of saponins and flavonoids after intravenous administration of Jiweiling freeze-dried powder, which may provide some references to the apprehension of the action mechanism and clinical application.