Use of micellar partition in capillary isotachophoretic focusing

The influence of micelles of nonionogenic surfactant in the leading electrolyte on improvement of separation of dinitrophenyl and dansyl derivatives of amino acids and position isomers of nitrophenols by isotachophoretic focusing was studied. The use of micelles enabled or improved the separation of above mentioned substances. The method combines in a single step the advantage of improvement in separation efficiency by use of micelles, applied for this purpose mostly in capillary zone electrophoresis (micellar electrokinetic chromatography), with the advantage of analyte focusing by the isotachophoretic technique. The experiments were carried out in instrumentation with a tapered channel in the separation compartment. At least a 10-fold increase of concentration of analytes in detector in comparison with sample and complete analyses at applied voltage up to 1 kV was achieved.