PREDICTING PEAK SYMMETRY IN CAPILLARY-ZONE-ELECTROPHORESIS - BACKGROUND ELECTROLYTES WITH 2 CO-IONS - SCHIZOPHRENIC ZONE BROADENING AND THEROLE OF SYSTEM PEAKS

This paper investigates fundamental phenomena in the migration behavio r of analytes in the very frequent case in current capillary zone elec trophoresis practice of using background electrolytes with two co-ions . It is shown that in such background electrolyte systems there always exists a regular system phenomenon which brings enormous electromigra tion dispersion to certain analytes. The analytes which yield to this phenomenon may be predicted by calculating the so-called velocity slop e Sr, which is a measure of zone symmetry and broadening. On the examp le of a simplified model system, it is shown explicitly that these ana lytes coincide by their mobilities with the mobility of the system pea k. The explanation for these effects is given on the basis of schizoph renic behavior where one and the other co-ions force the analyte zone to be fronting and tailing simultaneously. Detailed theoretical descri ption of the behavior of analyte zones in binary co-ion background ele ctrolytes is presented using peak shape diagrams that provide a compre hensive view of their electromigration dispersion characteristics. Exp erimental verification of the theory is given, together with a detaile d discussion of the effect of the background electrolyte composition o n the magnitude and extent of appearance of schizophrenic zone broaden ing.