NONUNIFORM ELECTRICAL-FIELD EFFECT CAUSED BY DIFFERENT CONCENTRATIONS OF ELECTROLYTE IN CAPILLARY ZONE ELECTROPHORESIS

Capillary zone electrophoresis is usually performed with uniform electrolyte concentrations in the electrolyte reservoirs and the capillary and a resultant uniform electrical field. Thus, the sample species migrates as the algebraic sum of electroosmotic flow mobility and ionic mobilities. A non-uniform electrical field can be formed by filling the capillary and outlet reservoir with electrolyte at a given concentration (initial electrolyte) and the inlet reservoir with a different electrolyte concentration of the same chemical species (replacement electrolyte). Application of an electrical field causes continuous entrance of the replacement electrolyte changing the conductivity consequent to electrolyte concentration. Therefore, the electrical field strength is not uniform along the capillary. In this paper we will discuss the effect of this non-uniform electrical field on migration rates of different sample ions as well as its application to model samples. © 1990.