Presented herein is a ligand-assisted elution chromatography process for the separation of metal ions using a sorbent. In particular, the present invention discloses a process of two sets of column system in combination with two sets of eluting ligand solutions to prepare substantially pure rare earth elements, wherein the first set of column comprises strong acid cation exchange resins and the second set of chromatographic columns comprises hydrous polyvalent metal oxide selected from the group consisting of TiO2, ZrO2, or SnO2 and wherein ligand of said second ligand solution coordinates with said hydrous polyvalent metal oxide.