Separation and Purification of Liquiritigenin by Ultrafiltration‐Solid Membrane Complexation Extraction Coupling Technology

An ultrafiltration‐solid membrane complexation extraction and reverse extraction method was developed for the separation and purification of liquiritigenin in licorice ultrafiltration, using ultrafiltration as the precursor technology. The effects of ultrafiltration pH, extraction time and three‐phase flow rate on the single‐stage extraction and reverse extraction rates of liquiritigenin in solid membrane were investigated, then the applicability of the single‐stage process to the cascade solid membrane was investigated. The optimum cascade solid membrane process was obtained with ultrafiltration pH=6, extraction time of 36 h and three‐phase flow rate of ultrafiltration: extractant: reverse extractant=188 : 188 : 94 mL min −1 , under which the total transfer rate of liquiritigenin was 75.73 %. The results showed that the solid membrane single‐stage process was equally applicable to cascade solid membranes, and the results may provide a novel technology with high efficiency, environmentally friendly and low‐cost for the separation of flavonoids in licorice.