Separation Of Giycyrrhizic By Aqueous Two-Phase Extraction System

In this paper separation of giycyrrhizic ammonium salt by aqueous two-phase extraction system of PEG/ (NH4) 2SO4 , ethylene oxide-propylene oxide random copolymer(EOPO)/KHP/water systems and the phase separation of various salts and organic solvent for two-phase aqueous extraction such as EtOH/K2HPO4 systems were studied .The results showed that the optimal aqueous two-phase extraction system of PEG/ (NH4) 2SO4 was 28%(w/w) PEG600, 14%(w/w) (NH4) 2SO4 . The influences of pH and temperature on this system were also studied .The partition coefficient K could reach 248.4 and the yield of giycyrrhizic ammonium salt reached 99.7%. But the tenacity of PEG was too high to extract giycyrrhizic from PEG , so this method was not a good way of separation of giycyrrhizic ammonium salt in industry .The techniques for separation of giycyrrhizic ammonium salt by aqueous two-phase extraction combined with temperature-induced phase separation in ethylene oxide-propylene oxide random copolymer(EOPO)/KHP/water systems was investigated .The optimum conditions were EOPO L64 28%(w/w), K2HPO4 32%(w/w), the yield of giycyrrhizic ammonium salt could reach 68.4%. The separation technique for giycyrrhizic from giycyrrhiza uralensis fisch was also investigated .The optimum conditions were EOPO L64 28%(w/w), K2HPO4 24%(w/w), temperature-induced condition was 63 ℃ and 120min. Particularly, EOPO can be reused circulative, and the performance of production was satisfied , it contains 11.3% giycyrrhizic ammonium salt . So this technique will be used in separation and extraction of traditional Chinese medicines.The phase separation behavior of various salts and organic solvent for two-phase aqueous extraction was studied . According to the variation of organic solvent phase volumes, the partition behavior of giycyrrhizic ammonium salt in EtOH/K2HPO4 systems was investigated . When Vtotal =10ml, the optimum conditions were V EtOH:VH2O=3:2, m(K2HPO4)=1.5g , The partition coefficient K could reach 12.8, theyield of giycyrrhizic ammonium salt reached 98.3%. The production is white , straggling, which contains 13% giycyrrhizic ammonium salt. Compare with traditional methed, it is simple and the appearance of production is good as well as the purity of production is high.