Column technology for capillary electromigration methods

Separation of analytes in capillary electrophoresis (CE) is often hindered by their interactions with silanol groups on the inner surface of the fused-silica capillary. In particular, the positive charges of basic proteins establish electrostatic interactions with the negative charges at the capillary surface, leading to peak broadening and loss of separation efficiency. Moreover, uncontrolled electroosmotic flow (EOF) severely impacts analyte mobility with a loss of resolution or efficiency. This chapter summarizes the most widely used methods to mask capillary surface silanols in order to reduce sample adsorption and control EOF with the aim of enhancing separation performance. The use of small molecules and polymers as dynamic coatings is discussed as well as permanent coatings. Similarly, the use of nanomaterials, such as nanoparticles and carbon nanostructure, as capillary wall modifiers is described.