Homologues separation is a key process in the production of high-purity drugs and chemicals. High-purity phosphatidylserine (PS) is widely used as drugs and functional additives; however PS often appears in a mixture with structurally similar homologues and the selective separation of phospholipid homologues remains challenging. Here

a novel extraction method was developed to separate PS and phosphatidylcholine (PC) with ionic liquids (ILs) as extractants. The effects of structure and concentration of ILs and temperature on extraction performance were investigated. The results showed that the structure of the IL's anion had a significant impact on the separation selectivity

and an obvious synergistic extraction effect between IL and polar diluent was observed. In 1-ethyl-3-methylimidazolium bromide([EMIm]Br)-methanol-hexane biphasic systems

the selectivity of PC to PS (SPC/PS) reached up to 29.48

when the mole fraction of IL was only 5%. Additionally

ab initio calculations were used to explore the extraction mechanism

and the results indicated that the multiple hydrogen-bonding and electrostatic interactions were formed between phospholipids and ILs

which is probably beneficial for the selective separation of phospholipid homologues.