What is the principle involved in column chromatography?

Column chromatography involves a stationary solid phase which absorbs and separates the compounds passing through it with the assistance of a liquid mobile phase. The stationary phase is a solid material packed inside a column. Typical stationary phases include silica gel or alumina. The choice of stationary phase depends on the nature of the sample and the goal of the separation. The mobile phase is added to the top and flows down through the column by gravity or external pressure. This is also known as the eluent or solvent. On the basis of their chemical nature, elution is based on the differential adsorption of a substance by the adsorbent.