Column chromatography involves the separation of components over a column of stationary phase. The stationary phase material can be alumina, silica gel.
Procedure :
- A slurry of the stationary phase material is filled in a long glass tube provided with a stopcock at the bottom and a glass wool plug at the lower end.
- The mixture to be separated is dissolved in a suitable solvent and then it is loaded on top of adsorbent column.
- A suitable mobile phase which could be a single solvent or a mixture of solvents is then poured over the adsorbent column.
- The mixture along with the mobile phase slowly moves down the column.
- The solutes get adsorbed on the stationary phase and depending on the degree to which they are adsorbed, they get separated from each other.
- The component which is readily adsorbed are retained on the column and others move down the column to various distances forming distinct bands.
- The component which is less strongly adsorbed is desorbed first and leaves the column first, while the strongly adsorbed component is eluted later.
- The solutions of these components are collected separately.
- These different components can be recovered by evaporating the solvent.
