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

Coated capillaries can be advantageous in many capillary electrophoretic ap plications where nonaqueous background electrolytes are used. In the presen t work, a new dynamic polymer coating (poly(glycidylmethacrylate-co-N-vinyl pyrrolidone)) for methanol-based background electrolytes is introduced. The magnitude and stability of electroosmotic flow was investigated with coate d 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 h and, at pH* 3 a weak, unstable electroosmotic flow was observed, due to a c hange in the conformation of the polymer under acidic conditions. The dynam ically coated capillaries were successfully applied to the separations of c ationic drugs, phenols, and benzoic acids. The synthesis and characterizati on of the polymer are described in detail.