Extraction and purification of chlorogenic acid from ramie (Boehmeria nivea L. Gaud) leaf using an ethanol/salt aqueous two-phase system

Flow chart of extraction and purification of CGA using ethanol/salt ATPS. [Display omitted] •A much cheaper, greener and easier alcohol/salt ATPS was used to extract and purify CGA from ramie leaf.•The phase-forming alcohol and salt were recycled to reduce the cost.•The thermodynamics and kinetics in extraction procedure were studied.•This alcohol/salt ATPS is more feasible to scale-up in production. In this paper, an aqueous two-phase system (ATPS) based on ethanol/NaH2PO4 was used in separation and purification of chlorogenic acid (CGA) from ramie leaf. CGA was firstly extracted from dried ramie leaf powder by ethanol solution, then was added into ATPS for further purification. During the ATPS extraction procedure, the influencing parameters of type and concentration of salt, extraction temperature and pH were investigated. The experiments results demonstrated the CGA were extracted into alcohol-rich phase with impurities being extracted into salt-rich phase, the phase-forming components were recycled to reduce the cost after extraction. Furthermore, the thermodynamics and kinetics during the extraction procedure were simultaneously studied for the first time. This much easier, greener and cheaper alcohol/salt ATPS was more feasible for large-scale production.