New Type Aqueous Two-phase Liquid-liquid Equilibrium And The Study On Extracting Salt Glycyrrhizanate

Aqueous two-phase extraction is a high efficient and mild technology. It's especially fit for biotechnological products' separation and purification. For the material of aqueous two-phase such as PEG and Dextran are quite expensive, the industrialized examples are very few. As a matter of fact, developing cheap aqueous two-phase system becomes the technology developmental direction.This dissertation is mainly researching the distribute rule of the new type aqueous two-phase system of organic solvent / inorganic salt, and extracting Chinese traditional medicine-salt glycyrrhizanate from liquorice by ethanol / (NH4)2SO4 system. The mainly content as following:(1) Set up a method to judge the separate phase ability of common organic solvent / inorganic salt in aqueous two-phase system. The experimental results indicate: the less of Pup/Psolvent, the stronger ability of separate phase; the process of is the one that organic solvent and inorganic salt contests water molecule. The weaker hydrate ability of organic solvent, the ability of separate phase is stronger; the stronger salt out ability of inorganic salt, the ability of separate phase is stronger.(2) Measuring the solubility curves of the ethanol (2-propanol) / (NH4)2SO4 systems, and protracting their phase charts. Set up a method to measure the liquid-liquid equilibrium data of the ethanol (2-propanol) / (NH4)2SO4 systems.(3) Forecasting the relationship of three elements liquid-liquid equilibrium of ethanol (2-propanol) / (NH4)2SO4 aqueous two-phase systems at 30 C from two elements systems model parameters by the Scatchard-Hildebrand equation and the Fowler-Guggenheim equation, which is not very ideal compared with experimental data. Establishing an iterative calculative method to solve three elements liquid-liquid equilibrium equation, which makes the eleven variables reduce to three variables. The results indicate this method is very good. Correlating the relationship of the organic solvent/ inorganic salt systems liquid-liquid equilibrium by the Othmer-Tobias equation and the Bancroft equation, and the results is fairly good.(4) Extracting potassium glycyrrhizanate by ethanol / (NH4)2SO4 system at 30 C, and at the best experimental condition (the (NH4)2SO4 mess percent is 17.70%, the ethanol is 35.10%, the pH is about 6.0), the distribution coefficient K is up to 13.72 and the yield is up to 96.34%. Extracting ammonium glycyrrhizanate from liquorice by ethanol / (NR4)2SO4 system at the best experimental condition, obtained the mass concentration about 47.61% ammonium glycyrrhizanate and the yield 77 s up to 2.33% relative to the liquorice. By this new aqueous two-phase system can get higher concentration and higher yield ammonium glycyrrhizanate than the traditional acetone circumfluence crystal method.