Solubility and cosolvent
After adding a co-solvent to the binary system composed of the extracted components and the supercritical CO2 fluid, the solubility of the supercritical CO2 fluid has changed.
Experimental studies have shown that: solubility has a great relationship with the type and proportion of co-solvents.
4 case explanations on supercritical CO2 co-solvent extraction of herbal
How to use supercritical CO2 to extract ephedrine derivatives with entrainer？
Studies have found that the hydrochloride of ephedrine derivatives is almost insoluble in supercritical CO2. Using a single methanol as a co-solvent has an unsatisfactory solubilizing effect. Using methanol containing 10% ethylenediamine as a co-solvent can significantly improve ephedra. The solubility of alkali derivative hydrochloride in supercritical mixed solvent, ethylenediamine as a reaction co-solvent to convert the alkaloid in salt form into free alkali.
How to use supercritical CO2 to extract colchicine with cosolvent？
Five organic solvents such as ethanol were used to pre-soak the colchicum tuber, and then the supercritical CO2 fluid extraction study was carried out. The results showed that the extraction efficiency was greatly improved by soaking compared with non-soaking.
After immersing in ethanol for 15 minutes, and extracting for 35 minutes under the conditions of 35MPa and 40°C, the one-time extraction rate can reach 80%. The mass fraction of colchicine has increased from 0.185% in the original plant to 6.92% in the extract. Nearly 38 times.
However, it is difficult to extract colchicine in samples without immersion treatment, and only 3% extraction rate can be obtained under the same extraction conditions.
Does supercritical CO2 extract ginseng need a cosolvent?
Using supercritical CO2 fluid to extract ginseng saponins in ginseng, using methanol or dimethyl sulfite as a co-solvent can increase the extraction rate. Compared with traditional organic solvent extraction methods, the extraction is faster and more effective, and the extraction rate is as high as 90%.
What is the effect of using entrainer supercritical CO2 to extract alkaloids?
Compared with the traditional methods, the supercritical fluid technology is simpler, more economical and environmentally friendly than the solvent method and steam distillation method for the extraction of alkaloids.
In the extraction of alkaloids from traditional Chinese medicine, because of the great polarity of alkaloids, the solubility of alkaloids in fluids can not be changed by simply increasing the pressure of extraction. Therefore, can be improved by adding the cosolvent.
Through the comparison of extraction time, pressure first-order temperature equal to ethanol dosage, determined the influence of single variable on alkaloid extraction, and further explored the optimal experimental conditions: extraction pressure 25 MPa, extraction temperature 60 C, extraction time 3 hours, ethanol dosage 200 ml, alkaloid extraction rate 0.192%.