Study on the Extraction of Total Flavonoids from Glycyrrhizae Radix et Rhizoma by Ammonia and the Purification of Ultrafiltration

OBJECTIVE To establish a suitable method for industrialized production of total flavonoids extraction and purification from Glycyrrhizae Radix et Rhizoma. METHODS The orthogonal test was used to determine the best extraction conditions within the extraction rate of total flavonoids as the index; and orthogonal experiment was used to optimize the parameters of ultrafiltration process taking the transfer rate of total flavonoids and the ratio of removal of impurity as indexes. RESULTS The best extraction conditions were as follows: 24 times of 0.75% ammonia, extract 3 times, 60 min for each time, the average extraction rate of total flavonoids was 83.5%. Ultrafiltration results showed that: 10 nm of inorganic ceramic membrane, in the operating pressure of 0.12 MPa and liquid temperature of 25 ℃, the average transfer rate and average removal rate of total flavonoids were 95.6% and 23.3%. CONCLUSION The combined technique is simple and feasible, and the production cost is low, the method is suitable for industrial application.