Optimization of the Extraction of Ketone II_A by Supercritical CO_2 Using Uniform Design

The technique for the extraction of Ketone ⅡA by supercritical CO2 was optimized using uniform design.The effects of extraction temperature,pressure and time on Ketone ⅡA yield were discussed,and Ketone ⅡA content was determined by HPLC.A yield of 81.36% achieved under the optimal conditions as follows: extraction temperature 35℃,extraction pressure 40 MPa,extraction time 0.5h and CO2flow rate 20 kg/h.Compared with the other extracting methods,the yield was high,the selectivity was higher together with no environmental pollution,which may achieve an applicable value for the extraction of betulin.