[header] How to perform column chromatography [title] Read and understand the lab procedure. [step] The goal of column chromatography is to separate and collect the desired chemical components from a mixture. Separation will occur within a column containing a stationary adsorbent and a mobile eluent (solvent). 
An impure sample is introduced to the column and eluted (or separated) by running eluent through the column. Separation will occur because your impure mixture is made up of different chemical components that will be unevenly adsorbed (attached) to the surface of the adsorbent.