SEPARATION OF POLYELECTROLYTES OF VARIABLE COMPOSITIONS BY FREE-ZONE CAPILLARY ELECTROPHORESIS

Capillary electrophoresis (CE) of a series of random copolymers of the ionic monomer, sodium 2-acrylamido-2-methylpropanesulfonate (AMPS), a nd the nonionic monomer, acrylamide (AAm), was carried out. The absolu te value of the electrophoretic mobility mu(E) increases as expected w ith AMPS content. However, mu(E) clearly shows a discontinuity when th e reduced polymer linear charge density, xi, becomes unity. This pheno menon is a confirmation of Manning's counterion condensation theory. I t is concluded that free-zone CE can be used to separate and character ize charged copolymers below xi=1.