Novel stationary phase with regulated anion exchange capacity

A novel stationary phase - phenylaminopropyl (PLA) bonded silica - is proposed for anion-exchange chromatography. Low basicity (pKa about 2.5) attached to silica phenylaminopropyl groups allows a variation of surface density of protonated sites in the pH range from 2 to 5. This enables us to use the same column for the separation of anions having different affinity to anion-exchangers. The effect of mobile phase pH on conditional capacity of PhA-silica was studied. The hypothesis on dependence of ion-exchange selectivity on the column capacity is discussed. Suitability of PhA-silica for ion-chromatographic separation of organic and inorganic anions at different pH values of eluent was demonstrated. © 2001 Elsevier Science B.V.