A novel hydrophilic polymer-based anion exchanger grafted by quaternized polyethyleneimine for ion chromatography

A novel hydrophilic polymer-based anion exchanger has been described for ion chromatography (IC). It is prepared by grafting polyethyleneimine (PEI) onto the poly(glycidylmethacrylate-divinylbenzene) (GMA-DVB) substrate, followed by hydrolytic treatment to convert the residual epoxide groups onto the surface of GMA-DVB substrates to hydroxyl groups, finally quaternized PEI by a molecule containing epoxide group. Hydrophobic surface of GMA-DVB substrate can be converted to hydrophilic, aiming to reduce unwanted non-ionic interaction from the substrate. After optimizing the reaction conditions, the obtained anion exchanger showed good separation towards standard inorganic anions under the suppressed mode and complete elution of seven common inorganic anions could be achieved in less than 16 min by using potassium bicarbonate eluent. It also demonstrated fast dynamic kinetic and enabled the separation of 7 anions within 3 min at the isocratic mode. Column efficiency of the anion exchanger was up to 34,000 /m.