PRESSURIZED FLOW-DRIVEN CAPILLARY ELECTROCHROMATOGRAPHY USING ION-EXCHANGE RESINS

Capillary electrochromatography using cation and anion exchange resins under pressurized flow is demonstrated to be applied to the separatio n of charged solutes, such a lanthanide ions. The typical variation of elution order for the mixture of sulfite, sulfate, and thiosulfate io ns, the reduction and extension of elution times due to the applicatio n of high voltage, and the simultaneous separation of cations and anio ns are demonstrated. A minor component appears by shifting the elution time of a major component while applying a high electric field. The e lectric resistance of the column was measured under electrochromatogra phic conditions, and its dependence on the applied voltage has been di scovered. From the relationship between elution times and applied volt age, the sum of electrophoretic mobility of an ion and electroosmotic mobility is estimated for landthanide cations. The capacity factor in electrochromatography is found to depend, to some extent, on the poten tial gradient. (C) 1997 John Wiley & Sons, Inc.