Analytical Sciences

Abstract − Analytical Sciences, 27(9), 885 (2011).

Counter-ionic Effect on the Separation of Water-soluble Compounds Applying a Hydrophilic Stationary Phase Bonded with a Zwitter-ionic Polymer§
Waka KAMICHATANI,* Yoshinori INOUE,* Mitsuru SAITO,* Yasuyuki KOBAYASHI,** and Atsushi YAMAMOTO**
*Nippon Filcon Co., Ltd., 2220 Ohmaru, Inagi, Tokyo 208-8577, Japan
**College of Bioscience and Biotechnology, Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501, Japan
A novel hydrophilic stationary phase bonded with a zwitter-ionic polymer for HPLC was synthesized. The stationary phase, in combination with a mobile phase containing various salts, was evaluated for its ability to separate water-soluble compounds, such as nucleobases, nucleosides and glycosides. The retention of a large majority of the solutes, except for cytosine, was increased by adding anti-chaotropic ions to the mobile phase. These results suggested that the retention of solutes depended on the thickness of the hydration layer on the stationary phase. In the zwitter-ionic polymer adsorbent, the formation of the hydration layer and the ionicity of the zwitter-ionic group on the stationary phase will be controlled by the properties of the ions added to the mobile phase.