Classical examples of group separations:

Every of these groups has different activity that increases in the following order: Bound  <  free <  H-bond.

According to current models of adsorption procedure, it is supposed that adsorption sites are fully covered through either of solute or solvent molecules which are adsorbed depending on their associative strength in this competitive interaction. The competition between the solute and the mobile phase molecules for an active site provides the driving force and selectivity in separations. Interaction between a solute molecule and the adsorbent surface is best when functional groups overlap adsorption sites. The Adsorption chromatography is less influenced through difference in molecular weight but certainly more by functional groups. For compounds of low to moderate polarity, adsorption chromatography often makes possible the separation of complex mixtures into classes of compounds with similar chemical functionality. Classical examples of group separations are polynuclear aromatics from a petroleum sample and the triglycerides from a liquid extract.