Smart Dual-Responsive\nIonic Liquid as Transformable\nand Recyclable Media for Extracting and Separating Phytochemicals\nfrom Wild Rumex acetosa L.

In this work, a dual-responsive ionic liquid (DR-IL),\nnamely, [C<sub>4</sub>mim][FeCl<sub>4</sub>] was developed for simultaneously\nextracting\nand separating hydrophilic phytochemicals, including epicatechin (EC),\ndihydroquercetin (DQ), ferulic acid (FA), and hydrophobic phytochemicals,\nsuch as emodin (ED), chrysophanol (CP), and physcion (PC), from roots\nof wild Rumex acetosa L. The [C<sub>4</sub>mim][FeCl<sub>4</sub>] demonstrates considerable potential\nfor extracting and separating target phytochemicals through temperature\nadjustment and accelerated phase separation facilitated by a neodymium\nmagnet. Meanwhile, a high recovery yield is obtained by adding a magnetic\nfield. The overall extraction yield of target phytochemicals achieved\nby [C<sub>4</sub>mim][FeCl<sub>4</sub>] reaches 16.12 mg/g under the\noptimal extraction conditions, representing a 1.53–2.39-fold\nincrease compared to conventional solvents. Furthermore, the molecular\nsimulation and FT-IR analysis reveal that the synergistic effect of\nvan der Waals forces and hydrogen bonds significantly contributed\nto the higher extraction yields of target phytochemicals.