High performance capillary gel electrochromatography with replaceable media

Capillary gel electrochromatography is evaluated with an entangled polymer solution which is pumped into the capillary and run under fritless conditio ns. The polymer used has an acid backbone with grafted hydrophobic segments , the polyacid giving the electroosmotic flow and the hydrophobe segments p roviding the retentive component, Experimental evaluation of this type of s ystem reveals performance similar to capillary electrophoresis and other fo rms of electrochromatography. The analysis of plate height data demonstrate s that zone broadening is primarily due to diffusion with little contributi on from nonequilibrium zone broadening. Hence, operation at high velocities (high voltages) is most desirable as opposed to most chromatographic metho ds. Some of the advantages of this type of experiment include being able to replace the retentive media in a few minutes, fast and reproducible high-p erformance separation, and having a retention mechanism similar to reversed -phase liquid chromatography, Disadvantages include a low retentive phase c oncentration and hence low sample loadability and limited solvent compatibi lity of the polymer. A number of different separations are demonstrated inc luding separation of alkyl benzoates, alkylphenones, alkylbenzenes, oxidati on inhibitors, and PAHs.