In the direct enantiomer separation the most popular approach is use of chiral stationary phases. In this case the site of the chiral selector is on the stationary phase. Stationary phase consist of an inert solid support (usually silica microparticles) on to the surface of which a single enantiomer of a chiral molecule (selector) is either coated/adsorbed  or chemically linked and that forms the chiral stationary phase. Commonly used chiral selectors include polysaccharides, proteins, cyclodextrins, etc. An interesting review of chiral stationary phase development and application in chiral analysis appeared in [https://www.chromatographyonline.com/view/review-chiral-stationary-phase-development-and-chiral-applications LCGC] magazine, 2011.