PREDICTION OF THE MIGRATION BEHAVIOR OF ANALYTES IN CAPILLARY ELECTROPHORESIS BASED ON 3 FUNDAMENTAL PARAMETERS

The prediction of analyte migration behavior in capillary electrophore sis (CE) is essential for rapid method development. The dynamic comple xation model, based on 1:1 interactions, was used to accurately predic t the apparent electrophoretic mobilities and the migration times of a group of deoxyribonucleotides (dNPs) at various concentrations of bet a-cyclodextrin (beta-CD). The electrophoretic mobility of the analyte, the electrophoretic mobility of the analyte-additive complex and the equilibrium constant are the three fundamental parameters required to determine the mobility of an analyte. The apparent migration time of t he analyte can be predicted once the electroosmotic mobility and relat ive viscosity of the solution are known. Optimum separation conditions can be determined based on these parameters. Excellent agreement betw een observed analyte migration behavior and predicted values was demon strated, with relative errors being often less than 1%. The theory was tested repeatedly under various conditions in order to assess its pre dictive capabilities and limitations. Analysis by molecular modelling, in conjunction with calculated electrophoretic parameters and equilib rium constants, provided deeper insight into the probable mechanisms o f the separation process at the molecular level. (C) 1997 Elsevier Sci ence B.V.