Interpretation of the excess adsorption isotherms of organic eluent components on the surface of reversed-phase phenyl modified adsorbents

The adsorption of three organic eluent components (acetonitrile, methanol, and tetrahydrofuran) from water were measured on four phenyl-type bonded phases using the minor disturbance method. The thicknesses of organic layer enriched above the phenyl-type bonded ligands were assessed and interpreted. Acetonitrile and tetrahydrofuran showed multilayer formation while methanol showed monomolecular adsorption. These results were compared to those obtained on alkyl bonded phases.