Studies On Extraction Ginkgo Flavonoids Process Of Supercritical CO₂

The active ingredients of natural products are important raw materials in pharmaceutical industry, the ginkgo flavonoids are especially the research focus in the study of Chinese traditional medicine. The separating methods of ginkgo flavonoids appeared many times in documents. It includes two kinds, one is solvent digestion, this method applies to making primary product, the other is deep-processing using colophony, chromatography and enzyme. All these methods have shortcomings, such as low yield and recovery, the product cant avoid remainder due to using butanone methanol and chloroform, especially instability. poisonous ginkgoic acid is not effectively controled. Content of it reached 1700μg/g in some samplers. SFE is a new technique. it is applied to food, medicine and chemical engineering. in food field, it includes hop, caffeine, essence and pigment. SFE has been called green extraction. Because it imposes good separation, fast ratio, easy operation, high purity and no poison.In this paper. first, SCF extraction with liquid was studied, this method combined SFE extraction with ethanol extraction. It was the keystone of the paper. we found optimum technology by single factor and orthogonal experiment. Second, we studied SCF Extraction with solid, this method carried on direct extraction, we also got optimum technology of this method. third, we studied method of ethanol extraction. we consider proportion of material and liquid, extraction time , temperature and ethanol concentration. at last, we got optimum technology.The theoretical analyses and experimental results showed that: (i)CO2 SCF with liquid extracted ginkgo flavonoids. In the condition of low pressure, the factors of pressure , time , temperature all affected it. Flavonoids were separated from the strong polarity substance including proanthocyanidin and tannins, and the low molecular lipid soluble substance, the optimum technology of extraction rate was 30MPa, 45 °C, 40min, 24L/h by orthogonal Experiment, but the purity was 30MPa, 30°C, 40min, 24I7h, so synthesis them, pressure was 30MPa, temperature was 30 °C, time was 40min, CO2 flow was 24L/h. in this condition, we did experiment three times. The extraction rate result was 3.27%, the purity was 64.7%. the ANOVA showed pressure affected evidently.(ii) COt SCF with liquid with solid needed high pressure, the extraction rate was low. The optimum technology of extraction rate was 100 item, 35 °C, 60min, 18L/h by orthogonal Experiment, but the purity was 100 item, 45°C, 120min, 18L/h, so synthesis them, material size was 100 item, temperature was 45 °C, time was 120min, CO2 flow was 18L/h. in this condition. We did experiment three times, the extraction rate result was 0.069%, the purity was 53.7%.(iii)Solvent of ethanol and water extract ginkgo flavonoids, temperature, time, ethanol concentration, and proportion of material and liquid all affected result, the optimum technology of extraction rate was 80°C, proportion of material and liquid 1:20, ethanol concentration 50%, time 3h by orthogonal experiment, but the purity was 60°C, proportion of material and liquid 1:25, ethanol concentration 50%, time 3h, so synthesised them, proportion of material and liquid was l:25,temperature was 60°C,time was 3h,ethanol concentration was 50% .in this condition, we did experiment three times, the extraction rate result was 3.51%,the purity was 7.8%.