Development of the water-holding separation materials having hydration layer associated with zwitter-ionic moieties as stationary phases

Abstract

Novel water-holding separation materials (Betaine-resin and DAM-resin) having zwitter-ionic functional groups were synthesized by introducing sulfobetaine and diallylamine-maleic acid copolymer to a hydrophilic methacrylate base resin. These separation materials showed high water-holding ability equal to ion-exchange resins. Their extraction efficiencies of watersoluble compounds in acetonitrile solutions were evaluated by the solid-phase extraction method using cartridges packed with the materials. The materials showed high affinity for nucleobases, nucleosides and organic acids, and could be extracted quantitatively. The DAMresin could quantitatively extract highly water-soluble solutes, such as glucose and glucosides. Therefore, the chromatographic properties for the water-soluble solutes on the DAM-resin were evaluated by HPLC. Because the logarithm of the retention factors (Log k) of the watersoluble solutes showed good correlation to their Log Po/w (logarithm of octanol-water partition coefficient), it was recognized that the water-soluble compounds should be able to be partitioned into the water-rich layer associated with the zwitterionic moieties. On the other hand, the ionic solutes were retained by a mixed interaction mode combined with an electrostatic interaction. However, their retentions could be regulated by controlling the composition of the copolymer, the characteristic of salt in the mobile phase, and the mobile phase pH. Furthermore, a fibrous adsorbent (DAM-fiber) was successfully developed by the wet-spinning of viscose rayon with the DAM, and was characterized for the extraction and adsorption of water-soluble compounds. Further, the DAM-fiber also showed high decline rates for volatile acidic and basic substances in atmosphere, and demonstrated a high ability as an adsorption/removal material for odor substances. © 2014 The Japan Society for Analytical Chemistry.