Simultaneous enantioseparation of citrus flavonoids in chiral microemulsion electrokinetic chromatography using deep eutectic solvents.

A novel, deep eutectic solvent (DES)-assisted sodium cholate (SC)-chiral microemulsion electrokinetic chromatography method is presented for separation of five flavonoid glycoside enantiomers, namely hesperidin, naringin, narirutin, eriocitrin, and neoeriocitrin. Herein, we develop a novel, green DES, whose addition considerably enhances the separation performance through multiple synergistic effects. A series of factors notably affecting chiral separation are systematically optimized: type and concentration of cyclodextrin, DES, and SC, oil phase type, and pH. The microemulsion comprises 0.5 % (v/v) n-octanol, 0.6 % (v/v) DES prepared using betaine and citric acid, 20 mM 2-HP-β-CD, 100 mM scdium cholate hydrate, and 15 mM borax buffer under the optimized conditions. Enantioseparations of the five enantiomers are achieved within 7 min, with resolutions ranging from 1.29 to 2.88. The method developed provides an innovative and effective way for chiral separation of enantiomers in complex food matrices.