Employment of detergent-tag/solute interactions in capillary electrophoresis of neutral polysaccharides.
Neutral and inherently immobile polysaccharides are induced to migrate in an electric field through interactions with a detergent added to the electrophoretic electrolyte buffer. Before analysis the polysaccharides are converted to fluorescent derivatives to enable detection, but choice of a tag can also be utilized for modulation of the electrophoretic mobility. Three cases are discussed and exemplified, namely detergent-solute, detergent-solute+tag, and detergent-tag interactions. Anionic as well as cationic surfactants were exploited along with different derivatization reagents. Depending on the approach chosen, different kinds of information about sample composition and distribution(s) can be obtained, including degree of substitution, distribution of molecular weight (obtained in free solution without sieving media) and polymer conformation. A shift in polymer conformation upon a change in solvent composition can be monitored.