AUTOMATED ISOTACHOPHORETIC ANALYTE FOCUSING FOR CAPILLARY ZONE ELECTROPHORESIS IN A SINGLE CAPILLARY USING HYDRODYNAMIC BACK-PRESSURE PROGRAMMING

An automated isotachophoretic (ITP) analyte focusing procedure prior t o capillary zone electrophoresis (CZE) is described. The ITP focusing step is carried out in the same capillary as the CZE. Hydrodynamic bac k-pressure programming resulted in a reduction in the effects of the e lectroosmotic flow-rate during the ITP step and allowed the removal of terminating buffer before the CZE run was started. The characteristic s of this on-line focusing procedure were studied for several anionic test compounds.