The present invention is directed to a method of separating electrolytes by size exclusion chromatography using neutral microporous sorbent materials. Two types of sorbents have shown to be most promising: microporous non-functionalized hypercrosslinked polystyrene materials with a pore size comparable to diameters of hydrated electrolyte ions, and microporous activated carbons prepared by pyrolysis of hypercrosslinked polystyrene sorbent beads. In this method, a column comprising hypercrosslinked polystyrene sorbent beads is loaded with a solution of electrolytes, and then eluted with water. Electrolytes with the largest ions elute first, and those with the smallest ions elute last. Selectivity of separation rises with the concentration of the mixture to be separated. With concentrated initial mixtures, concentration of separated components exceeds their concentration in the initial mixture.