ISOTOPIC-SEPARATION OF [N-14]ANILINE AND [N-15]ANILINE BY CAPILLARY-ELECTROPHORESIS USING SURFACTANT-CONTROLLED REVERSED ELECTROOSMOTIC FLOW

Separation of isotopically labeled [N-14]- and [N-15]aniline was achie ved using capillary electrophoresis based on the isotopic effect on pK (a). The effects of the buffer co-ion, pH, and electroosmotic mobility on the resolution are investigated in this paper. Electroosmotic now (EOF) was controlled using the zwitterionic surfactant Rewoteric AM CA S U as buffer additive. The resultant EOF was anodic (reversed) and lo w in magnitude (0.6 x 10(-4) cm(2)/(V.s)). The resolution of [N-14]- a nd [N-15]aniline was 1.22. Addition of a cationic surfactant, cetyltri methylammonium bromide, to the zwitterionic surfactant increased the m agnitude of the anodic EOF. This EOF improved the resolution to 1.33 b ased on mobility counterbalance.