A novel composite stationary phase composed of polystyrene/divinybenzene beads and quaternized nanodiamond for anion exchange chromatography

An approach for preparation of a novel composite anion exchanger composed of polystyrene/ divinylbenzene (PS/DVB) beads and quaternized nanodiamods (QND) were proposed. Oxidized nanodiamonds (OND) were quaternized by the condensation polymerization between methylamine (MA) and 1,4-butanediol diglycidyl ether (BDDE), which were characterized by Fourier transform infrared (FTIR) spectra, X-ray phtoelectron spectroscopy (XPS), thermogravimetric analysis (TGA). QND with layers of cationic polyelectrolyte was attached onto the surface of sulfonated PS/DVB beads electrostatically. Subsequently, hyperbranched reaction of QND agglomerated on the PS/DVB bead surface was performed by the alternate reaction between MA and BDDE to increase the exchange capacity. The composite anion exchanger showed good stability in organic solvent and a wide pH range. The surface of these microspheres was characterized by scanning electron microscopy. In addition, ion exchange selectivity and separation efficiency of the anion exchangers were assessed using the mixtures of anions (F-, Cl-, NO2-, Br-, NO3-, HPO42- and SO42-) with carbonate/bicarbonate as eluent, and the anion exchanger with high exchange capacity could be used to analyze chloride in aqueous solution with high concentration of fluoride. This work explores the potential of nanodiamods as an agglomerated material for ion chromatography stationary phases for the separation of inorganic anions. (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.