Supercritical carbon dioxide with or without methanol and 95% ethanol modifiers was used to extract paeonol from the pills of Jisheng Shenqi Wan and high-performance liquid chromatography (HPLC) was used to analyze the extract. The effect of temperature and pressure on the yield of paeonol was tested. The results show that the recovery of paeonol was improved by adding a polar modifier, such as methanol and 95% ethanol in supercritical fluid. The yield obtained after 120 min extraction with 95% ethanol modified-supercritical carbon dioxide was the highest (1.51, w/w at 60 degrees C and 400 bar), while that obtained with supercritical carbon dioxide only at 40 degrees C was the lowest from 0.67 to 0.83 over a range of 200-600 bar.
Copyright 2006 John Wiley & Sons, Ltd.