Extraction Process of Amino Acids with Deep Eutectic Solvents-Based Supported Liquid Membranes

The separation and purification process of amino acids (AAs) accounts for 80% of the total production cost. So the development of new technology for the separation and purification of AAs is very important. In this research, supported liquid membranes (SLMs) based on deep eutectic solvents (DESs) were successfully applied for the extraction of AAs. A series of DESs were designed, synthesized, and screened to obtain suitable ones as the supported phase. Some important factors, such as effect of types of DESs and membranes, pH and concentration of Trp were investigated. Higher extraction efficiency was achieved. ChCl/PTS was found to be the most efficient one. Results show that the initial concentration of Trp in the feed phase is 0.1 mM, and pH = 1.0 in the feed phase and pH = 13.0 in receiving phase is optimal for extraction, under which the extraction efficiency can reach 86.1%. ChCl/PTS/Asp (1/4/1) of SLM has the best stability, the weight loss of SLM is 0.38%. Finally, H-1 NMR shows that the hydrogen bonding interaction between DESs and Trp is probably the main driven force for this specific process. This research would provide a new process for the separation and purification of AAs with SILMs technique.