Original

Study of a Capillary LC System using Temperature−Responsive Polymer−Modified Packing Materials

Masahito Kanezawa¹, Eri Ayano¹, Hideko Kanazawa^1†, Yoshikatsu Akiyama² and Teruo Okano²

¹ Kyoritsu University of Pharmacy, 1−5−30 Shibakoen, Minato−ku, Tokyo 105−8512, Japan.
² Institute of Advanced Biomedical Engineering and Science, Tokyo Women’s Medical University, 8−1 Kawadacho, Shinjyuku−ku, Tokyo 162−8666, Japan

Abstract:

We have developed a new method of HPLC packing materials modified with a temperature−responsive polymer, poly (N−isopropylacrylamide) (PNIPAAm). The surface properties and functions of the stationary phases are controlled by the external temperature. We could separate various pharmaceuticals, peptides and proteins by using only the aqueous mobile phase. In this study, we developed a capillary chromatographic system using packed PNIPAAm modified silica beads. We demonstrated the separation of steroids and phenylthiohydantoins (PTH)−amino acids on a capillary column by temperature control. The retention times of the analytes increased with increasing the temperature, and temperature−responsive elution behavior was observed. The result suggested that we can separate a trace amount of samples used in the pharmaceutical and biomedical fields by only changing the temperature in this system.

Keywords: poly (N−isopropylacrylamide) (PNIPAAm); capillary column; temperature−responsive chromatography; steroid; PTH−amino acid.

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