title: Retention characteristics of water-soluble compounds on water-holding adsorbents with immobilized zwitterionic copolymers having different ionicities.
abstract: Three kinds of water-holding adsorbents with immobilized zwitterionic copolymers having different cationic ionicities were synthesized. To investigate the influence of the charge balance and the ionicity of the cation site, the retention properties of the water-soluble solutes on the zwitterionic adsorbents were measured by HPLC. These adsorbents had high water contents, and the hydrating water contents depended on the amounts of immobilized copolymer. The retentions of water-soluble solutes depended on the hydrophilic interaction, and were in the order of logP(o/w)  (logarithm of octanol-water partition coefficient). This suggests that the partition to the hydration layer was the main retention mechanism on the zwitterionic adsorbents. On the other hand, the electrostatic interaction based on the cation site on the adsorbents was also observed. The electrostatic interaction could be reduced by decreasing the ionicity of the cation sites. These results indicate that the retentions of the water-soluble solutes on the zwitterionic adsorbents were greatly influenced by the ionicity of the cation sites on the adsorbents.
authors.affiliation: Products Planning & Development Department, R&D Center, Nippon Filcon Co., Ltd., Inagi-shi, Tokyo, Japan. w-kamichatani@filcon.co.jp
authors.forename: Waka
authors.initials: W
authors.lastname: Kamichatani
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Inoue
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Saito
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamamoto
mesh_terms: D000327:Adsorption; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D057927:Hydrophobic and Hydrophilic Interactions; D009705:Nucleosides / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D009705:Nucleosides; D011108:Polymers