INCREASED SELECTIVITY FOR ELECTROCHROMATOGRAPHY BY DYNAMIC ION-EXCHANGE

The separation of compounds with similar mobilities is expected to be difficult with capillary zone electrophoresis. Increased selectivity is shown for compounds of this type when other modes of separation are added to the system. A capillary coated with a hydrophobic stationary phase is shown to be a dynamic ion exchanger when a quaternary ammonium compound is added to the running buffer. Compounds are shown to have a decrease in retention when the concentration of the buffer ion is increased. The effect of adding an organic modifier and the influence of the concentration of the surface active reagent are also studied.