THE ANALYSIS OF PHARMACEUTICAL COMPOUNDS USING ELECTROCHROMATOGRAPHY

Electrochromatography couples the very high efficiencies associated with capillary zone electrophoresis, with reversed-phase liquid chromatography (RPLC). Therefore, electrochromatography couples the differences in electrophoretic mobilities of related species, with the modification of selectivities that are available to users of RPLC through variation of the stationary and mobile phases. Electrochromatography uses an electric field to drive the mobile phase through a packed capillary, and because the resulting flow profile is plug-like, very high efficiencies are achieved. Also, the linear flow through a packed capillary in electrochromatography is independent of the particle diameter, and since the driving force (electroosmosis) produces no hydrostatic pressure, it is possible to use very small diameter particles and consequently generate large theoretical plate values often > 300,000 plates per metre with reduced plate heights < 1. The capabilities of electrochromatography are demonstrated by means of the analysis of several drug compounds.