title: Separation of curcuminoids using ionic liquid based aqueous two-phase system coupled with in situ dispersive liquid-liquid microextraction.
abstract: An aqueous two-phase extraction system (ATPS) combined with an in situ dispersive liquid-liquid microextraction (DLLME) method using imidazolium ionic liquids (ILs) for the separation of curcuminoids is developed. The influence of structure of IL, the type of metathesis reagents, and the back extraction agents on the extraction efficiency is investigated. 2.0mg of curcuminoids are extracted by an IL ATPS composed of 0.4g 1,3-diethylimidazolium iodine (EeimI), 0.6g potassium hydrogen phosphate, 1.0g water. Then the bis[(trifluoromethyl)sulfonyl]imide lithium (LiNTf2) aqueous solution is added to the EeimI-rich phase of the ATPS. The water-immiscible ionic liquids, 1,3-diethylimidazole bis[(trifluoromethyl)sulfonyl]imide (EeimNTf2), forms by the metathesis reaction. The in situ DLLME is triggered simultaneously and further purifies the curcuminoids. 92% of EeimI transforms into EeimNTf2 and thus the Eeim(+) cation is used for twice in this method. Finally, 0.1mol/L NaOH aqueous solution is used as the back extraction reagent. The curcuminoids precipitate is achieved with 93% of recovery when the aqueous solution is adjusted to pH 3.0. This ATPS-DLLME method is successfully applied to the separation of curcuminoids from Curcuma Longa (0.96±0.02% of extraction yield, a purity of >51% with respect to the total dry mass of the product).
authors.affiliation: Institute of Biological Technology, Colleges of Life Sciences and Health, Northeastern University, Box H006, Shenyang 110169, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Shu
authors.affiliation: Institute of Biological Technology, Colleges of Life Sciences and Health, Northeastern University, Box H006, Shenyang 110169, China.
authors.forename: Mingcen
authors.initials: M
authors.lastname: Gao
authors.affiliation: Institute of Biological Technology, Colleges of Life Sciences and Health, Northeastern University, Box H006, Shenyang 110169, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Biological Technology, Colleges of Life Sciences and Health, Northeastern University, Box H006, Shenyang 110169, China.
authors.forename: Rusheng
authors.initials: R
authors.lastname: Song
authors.affiliation: Research Center for Analytical Sciences, Colleges of Sciences, Northeastern University, Box 332, Shenyang 110189, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.affiliation: Research Center for Analytical Sciences, Colleges of Sciences, Northeastern University, Box 332, Shenyang 110189, China. Electronic address: chenxuwei@mail.neu.edu.cn.
authors.forename: Xuwei
authors.initials: X
authors.lastname: Chen
mesh_terms: D011232:Chemical Precipitation; D030024:Curcuma / Q000737:chemistry; D003474:Curcumin / Q000031:analogs & derivatives* / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D059627:Liquid Phase Microextraction
chemical_list: D007093:Imidazoles; D052578:Ionic Liquids; D003474:Curcumin
keywords: Aqueous two-phase system; Curcuminoids; Ionic liquid; Liquid–liquid microextraction