Résumé
A new ultrasonic-assisted extraction (UANE) method coupled with solid phase extraction (SPE) using ultrasonic fountain was established for the extraction of eight common ginsenosides from leaves of Panax quinquefolium L. The extraction system has been designed and several experimental parameters,including the type and volume of extraction solvent,pH value and salt concentration of extraction solvent,type and volume of elution solvent,and amount of C18, extraction time were examined and optimized. Under the optimal conditions,the recoveries of ginsenosides were in the range of 96. 3% -110. 6%, the relative standard deviations (RSDs) were in the range of 2.8%-4.3%,indicating that the method has a good performance for the extraction of these ginsenosides. Compared with traditional UANE-SPE method, the modified method simplified the extraction device,shortened the extraction time and improved the extraction efficiency.
Résumé
<p><b>OBJECTIVE</b>To determine 20(S)-ginsengnoside Rh2 in the hydrolysis product of saponins from leaves of Panax qinquefolium.</p><p><b>METHOD</b>The separation was performed on ZORBAX EXEND C18 column (4.6 mm x 250 mm, 5 microm), eluted with methanol and water (85:15) as mobile phase with the rate of 1.2 mL x min(-1) at 25 degrees C, the wavelength for measurement was 203 nm.</p><p><b>RESULT</b>The calibration curve was linear in the range of 0.5-25 microg for 20(S)-ginsengnoside Rh2(r = 0.9999, n = 7). The average recovery was 99.7% (RSD= 1.0%).</p><p><b>CONCLUSION</b>This method is simple, accurate, reliable and reproducible. The result shows that the transform ratio of 20(S)-ginsengnoside Rh2 is high by this hydrolysis method.</p>