SEPARATION OF POLY(STYRENESULFONATES) BY CAPILLARY ELECTROPHORESIS WITH POLYMERIC ADDITIVES

The addition of hydroxyethyl cellulose lo the carrier solution employed in the capillary electrophoresis separation of poly-(styrenesulfonate) is shown to dramatically increase resolution over a wide range of molecular weight, allowing for the development of a high-resolution separation method. Wall-coated capillaries are utilized to reduce electroosmotic flow and to provide a surface with minimal interaction. This technique is compared with size-exclusion chromatography (SEC) and found to be favorably competitive for the analysis ot poly(styrenesulfonates) in terms of resolution, efficiency, and fractionating power; however, the speed of analysis is found to be approximately three times faster than SEC. The mechanism of separation, as determined by empirical curve-fitting and inspection of mobility plots, is thought to arise from size-selective sieving, as is the case for the separation of biopolymers by traditional slab gel electrophoresis. However, mobility does not adhere to the classical theoretical behavior of biopolymer electrophoresis, which is most likely due to the very large electric field that is utilized in these experiments. The advantages of the additive methodology for the analysis of synthetic polyelectrolytes of industrial significance are discussed in detail.