The compound to be analyzed is subject to a competition between:

• its adsorption on the stationary phase
• its solubilization in the eluent
• the adsorption of the eluent on the stationary phase

Two types of forces are involved when the eluent drives the solutes by adsorption chromatography:
⇒ Dissolution: solutes tend to dissolve in the eluent and migrate with it.
    In this case, it has to be effective enough to outweigh the adsorbent’s adsorption capacity.
⇒ Displacement phenomena: eluent molecules look for the same adsorption sites as solute molecules and thus displace them.