Novel dynamic polymer coating for capillary electrophoresis in nonaqueous methanolic background electrolytes.

Coated capillaries can be advantageous in many capillary electrophoretic applications where nonaqueous background electrolytes are used. In the present work, a new dynamic polymer coating (poly(glycidylmethacrylate-co-N-vinylpyrrolidone)) for methanol-based background electrolytes is introduced. The magnitude and stability of electroosmotic flow was investigated with coated capillaries at pH* values of 3, 7.8, and 10.4 in methanol. At pH* 7.8 and 10.4 the electroosmotic flow was negligible and repeatable. On the other hand, at pH* 3 a weak, unstable electroosmotic flow was observed, due to a change in the conformation of the polymer under acidic conditions. The dynamically coated capillaries were successfully applied to the separations of cationic drugs, phenols, and benzoic acids. The synthesis and characterization of the polymer are described in detail.