Displacement technique:

To develop a chromatogram by displacement technique, a displacer is introduced in to the mobile phase stream. The displacer has even higher affinity for the adsorbent than any of the components to be separated. Thus, on coming in to contact with the sites occupied by the most strongly adsorbed component, it will displace this component in the mobile phase and thus move on to the next group of the sites occupied by the next component which will then itself be displaced. Thus, the displacer drives the adsorbed components progressively along the column, every component displacing the one in front until they are eluted in the same order in which they were adsorbed on the column. The least strongly held is eluted first.