Basic equation for size exclusion chromatography:
The basic equation for size exclusion chromatography is
VR = V0 + KVL
where, VR is retention volume, V0 is the interstitial volume, K is some form of distribution coefficient and VL is the volume of water within the gel particles.
Normally, the K value greater than 1 is not encountered. If it is encountered, it implies the occurrence of phenomena like adsorption, hydrogen bonding and ion exchange between the gel matrix and the solute.