Capillary electrophoresis study on segment/segment system and its role in characterization of nanoparticles

Capillary electrophoresis (CE) coupled with contactless conductivity detector (C⁴D) was applied to characterize the migration of micellar segments under BGE/segment/BGE system, where a segment is a micellar phase surrounded by BGE. The transformation (non-ionic, ionic) → mixed micelles under the system was explained in terms of the features of the micellar phase discussed already in the literature. In the second part of the work, based on established phenomena for BGE/segment/BGE system, the BGE/segment/segment/BGE system was used to analyze the re-equilibration of two micellar phases (SDS│(TX-100/SDS)) during a run. This aspect was deeper analyzed with the conclusion that re-equilibration in the present system induces decomposition of the phase of mixed micelles by the phase of ionic micelles and this is a mechanism able to generate the boundary conditions. Established features for BGE/segment/segment/BGE system were further implemented towards preconcentration of nanoparticles and systematic studies show that the system in the configuration (SDS│(TX-100/SDS)) generates a trap state for nanoparticles. Due to this the preconcentration of nanoparticles, expressed in the terms of an enhancement factor (SEF_height), was found to reach level ca. 60.