Related Experiment Video
Updated: Aug 19, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Conformational effects on the performance and selectivity of a polymeric pseudostationary phase in electrokinetic
Jonathan P McCarney1, Robert D Loflin1, Erika Rauk1
1Department of Chemistry, University of Montana, Missoula, MT, USA.
Abstract:
The effect of the conformation of a polymeric pseudostationary phase on performance and selectivity in electrokinetic chromatography was studied using an amphiphilic pH-responsive polymer that forms compact intramolecular aggregates (unimer micelles) at low pH and a more open conformation at high pH. The change in conformation was found to affect the electrophoretic mobility, retention, selectivity, and separation efficiency. The low-pH conformer has higher electrophoretic mobility and greater affinity for most solutes. The unimer micelle conformation was also found to provide a solvation environment more like that of micelles and other amphiphilic self-associative polymers studied previously. It was not possible to fully characterize the effect of conformation on efficiency, but very hydrophobic solutes with long alkyl chains appeared to migrate with better efficiency when the unimer micelle conformation was employed. The results imply that polymers with a carefully optimized lipophilic-hydrophilic balance that allow self-association will perform better as pseudostationary phases. In addition, the results show that electrokinetic chromatography is a useful method for determining the changes in solvation environment provided by stimuli-responsive polymers with changes in the conditions.
Related Concept Videos
Ion-Exchange Chromatography
Gas Chromatography: Types of Columns and Stationary Phases
For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or...
Analyte Adsorption and Distribution
Capillary Electrophoresis: Applications
Capillary zone electrophoresis (CZE) separates ionic components based on their electrophoretic mobility. It has been used to separate proteins, amino acids,...
High-Performance Liquid Chromatography: Introduction
In HPLC, two phases play a critical role in the separation process:
Ion Exchange

