STUDY ON EXTRACTION OF PYRETHRINS WITH SUPERCRITICAL AND SUBCRITICAL CARBON DIOXIDE

摘要

Pyrethrins was extracted from the pyrethrum flowers with supercritieal and suberitical CO2. The effect of temperature, pressure and CO2 flow rate on the average concentration of pyrethrins in the presence of cosolvent (water) or not was discussed in orthogonal tests respectively. The pyrethrins were analyzed by GC-MS.The results show that the pressure and temperature are the major operating parameters affecting extraction. The optimized extraction conditions by the orthogonal tests are as follows: the pressure 18MPa,the temperature 35℃,CO2 flux 20L/h. The experiments also show that the water as cosolvent not only enhanced amount of extracted pyrethrins but enhanced selectivity of extraction.