Aliphatic mono and dicarboxylic acids have been separated on silica-based ion-exchangers under conditions commonly used in ion-exclusion chromatography. Various retention mechanisms including ion-exclusion, hydrophobic interaction, and adsorption are involved in the separation of these analytes. The contribution of each of these mechanisms can be manipulated by varying the characteristics of the chromatographic support like exchange capacity or type of the spacer molecule used for the binding of the sulfonate groups to the silica. Thereby, fine-tuning of the separation selectivity is possible.