General Chemistry Dictionary

"A ""chromatographic"" separation method with the ""mobile,"" liquid phase forced through the ""immobile"" phase by the application of an electrical potential difference, that is, by electroosmosis. In some cases, the separation is enhanced by electrophoresis. Chromatography is an analytical (see electroanalytical) separation technique based on the different attraction of the sample components to an immobile/stationary phase through which the sample solution is forced through by a flow of solvent. The sample components are adsorbed/desorbed on the surface of the stationary phase as they are flushed through by the solvent; consequently, they move with speeds inversely proportional to their adsorption strengths and become separated: the least-strongly adsorbed component is flushed out first and the most-strongly adsorbed last. A variety of stationary phases can be employed; the most common ones are: paper, thin layer of gelatinous material, or a column (or capillary) packed with small particles. "