Analytical Sciences

Abstract − Analytical Sciences, 18(1), 45 (2002).

Temperature-Responsive Chromatography Using Poly-(N-isopropylacrylamide) Hydrogel-Modified Silica
Hideko KANAZAWA,*  Tatsuo SUNAMOTO,* Eri AYANO,* Yoshikazu MATSUSHIMA,* Akihiko KIKUCHI,** and Teruo OKANO**
*Kyoritsu College of Pharmacy, 1-5-30 Shiba-koen, Minato, Tokyo 105-8512, Japan
**Institute of Biomedical Engineering, Tokyo Women's Medical University, 8-1 Kawadacho, Shinjuku, Tokyo 162-8666, Japan
Poly(N-isopropylacrylamide) (PNIPAAm) has the sharpest phase transition of the class of thermo-sensitive N-alkyl acrylamide polymers. We developed a new method of HPLC using packing materials modified with cross-linked poly(N-isopropylacrylamide) (PNIPAAm) hydrogel. A temperature-responsive surface was prepared by polymerization of NIPAAm in the presence of a cross-linker on the silica support. The surface properties and functions of the stationary phases change in response to the external temperature. Therefore it easily changes the interaction of a solute with the surface with a constant aqueous mobile phase. A temperature-responsive elution behavior was observed on the separation of steroids and PTH-amino acids. The method is expected to be applicable to separation in the pharmaceutical and biomedical fields.