Timothy S. Stevens

Surface Sulfonated Styrene Divinyl Benzene-Optimization of Performance in Ion Chromatography

Abstract When used with Ion Chromatography as a pellicular cation-exchanger, the optimum performance capacity of 50μ surface sulfonated styrene 2% divinyl benzene copolymer was found to be about 0.018 meq/g. This observation was at great variance with the theory and was explained by much slower diffusion of cations in this ion-exchanger relative to fully sulfonated ones. Slower diffusion was attributed to hindered swelling of the sulfonated polymer on the unsulfonated core and to varying percent sulfonation within the sulfonated region.

Hollow-fiber membrane systems as suppressors in ion chromatography

Abstract Ion-exchange hollow fibers have been used for exchange of cations in ion-chromatography effluents. The hollow fibers replace the conventional ion-exchange resin columns used to reduce the conductivity of the effluent by converting the sodium carbonate eluent to carbonic acid. The membrane system shows significant advantage over the dual ion-exchange column method in both ease of operation and superior stability of the chromatography system. Elution times and detector response for acetate ion, for example, were far more consistent and linear for the membrane system.