Temperature-Responsive Chromatography Using Poly(N-isopropylacrylamide)-Modified Silica
H Kanazawa1, K Yamamoto, Y Matsushima
1Kyoritsu College of Pharmacy, 1-5-30 Shiba-koen, Minato, Tokyo 105, Japan.
Analytical Chemistry
|May 31, 2011
Summary
A novel chromatography system uses temperature-responsive polymers on silica surfaces. This allows for controlled hydrophilic/hydrophobic changes, enabling effective separation of steroids and potentially peptides and proteins in aqueous solutions.
Area of Science:
- Analytical Chemistry
- Polymer Chemistry
- Separation Science
Background:
- High-performance liquid chromatography (HPLC) is a key separation technique.
- Modifying stationary phases can enhance separation capabilities.
- Temperature-responsive polymers offer tunable surface properties.
Purpose of the Study:
- To develop a novel HPLC system using temperature-responsive surfaces.
- To investigate the effect of temperature on stationary phase properties and analyte retention.
- To demonstrate the utility of this system for steroid separation.
Main Methods:
- Grafting poly(N-isopropylacrylamide) (PIPAAm) onto (aminopropyl)silica.
- Utilizing an activated ester-amine coupling method for polymer grafting.
- Packing HPLC columns with the modified stationary phase and analyzing mixed steroids at varying temperatures with an aqueous mobile phase.
Main Results:
- PIPAAm-grafted silica exhibited hydrophilic properties at low temperatures and hydrophobic properties at high temperatures.
- Steroid elution profiles were significantly influenced by mobile phase temperature.
- Retention times increased with temperature, with larger changes observed for hydrophobic steroids.
Conclusions:
- The temperature-responsive PIPAAm-modified silica enables external control over HPLC stationary phase properties.
- This novel chromatography system offers a new approach for separations using only aqueous mobile phases.
- The method shows promise for biological and biomedical applications, including peptide and protein separations.
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