Chromatographic behavior of poly(styrene-divinybenzene) encapsulated packing material for capillary elechochromatography

Poly(styrene-divinylbenzene) encapsulated silica (PS-DES) was synthesized a nd its characteristics as capillary electrochromatography stationary phase were studied. On capillary columns packed with this stationary phase, the e ffects of acetonitrile concentration as well as pH values on electroosmotic flow, and the effect of the latter on column efficiency were evaluated. Ar omatic hydrocarbons, polar and basic medicinal compounds were successfully separated by using reversed-phase elution. it was evident that selectivity based on pi-pi electronic interaction between solute and stationary phase m olecules contributed to the separation. Peaks in the chromatograms obtained were generally symmetrical. At a pH of the mobile phase as high as 11.2, t he stationary phase was still stable after more than 160 h of exposure. (C) 2001 Elsevier Science B.V. All rights reserved.