Application of ultrafiltration in the separation and purification of traditional Chinese medicine extracts

Traditional Chinese medicine is the general name of Chinese traditional medicine. Its use is based on the theory of traditional Chinese medicine. It has a unique theoretical system and application form, which fully reflects the characteristics of Chinese traditional culture and natural resources. According to the theory of Yin Yang and five elements, traditional Chinese medicine uses medicinal materials of different properties to complement each other and harmonize Yin Yang and five elements, so as to achieve the effect of treatment. Traditional Chinese medicine comes from plants, minerals and animals, especially plant medicinal materials. The chemical composition of plant Chinese herbal medicine is very complex, which usually contains alkaloids, amino acids, organic acids, phenols, saponins, steroids, terpenoids, proteins, mucus, tannins, sugars, starch, cellulose, inorganic salts.

On the other hand, traditional Chinese medicine mostly adopts compound prescription in the process of use. A compound composed of 4 ~ 5 traditional Chinese medicine may contain 300 ~ 500 chemical components. The natural nature of traditional Chinese medicine makes its chemical components very complex. The confirmation of its effective components (or effective parts) and separation and purification equipment are very important to improve the quality of traditional Chinese medicine and promote the internationalization of traditional Chinese medicine. The effective components of Chinese herbal medicine are mostly alkaloids, glycosides, ketones, etc. the extraction solvents are generally water and alcohol. The commonly used refining methods include alcohol precipitation, adsorption clarification, macroporous resin adsorption and ultrafiltration. A large number of precipitates appear in the process of alcohol precipitation. The adsorption and embedding of precipitates will cause the loss of effective components. Due to the strong selectivity of macroporous resin adsorption, it is difficult to retain the complex effective components in the compound, and the residue of clarifier also exists in the adsorption clarification method. In contrast, ultrafiltration membrane separation has the advantages of mild operating conditions, low energy consumption, simple operation and short process flow. At the same time, ultrafiltration can retain a certain range of components, so it has a unique role and great application potential in the traditional Chinese medicine industry. The application of ultrafiltration technology in the production process of traditional Chinese medicine can reduce the cost and improve the quality of traditional Chinese medicine.