Quantitative analysis of systematic errors originated from wall adsorption and sample plug lengths in affinity capillary electrophoresis using two-dimensional simulation

TitleQuantitative analysis of systematic errors originated from wall adsorption and sample plug lengths in affinity capillary electrophoresis using two-dimensional simulation
Publication TypeJournal Article
Year of Publication2007
AuthorsFang N, Li JW, Yeung ES
Journal TitleAnalytical Chemistry
Volume79
Pages5343-5350
Date PublishedJul
Type of ArticleArticle
ISBN Number0003-2700
Accession NumberISI:000247992600031
Keywords2 CO-IONS, BACKGROUND ELECTROLYTES, binding, constants, ELECTROMIGRATION, HYPERBOLAE, MATHEMATICAL-MODEL, monte-carlo-simulation, NUMERICAL-SIMULATION, PEAK DISPERSION, RECTANGULAR, ZONE-ELECTROPHORESIS
Abstract

Two-dimensional (2D) simulation of capillary electrophoresis is developed to model affinity interaction and wall adsorption simultaneously. Finite difference schemes are used to evaluate the mass-transfer equation in cylindrical coordinates. A Langmuir second-order kinetic law is applied to regulate the wall adsorption and desorption processes. Contributions from the simulation parameters are investigated extensively, and parameters for accurate and efficient simulation are identified. With the 2D model, capillary zone electrophoresis and affinity capillary electrophoresis (ACE) in the presence of strong or weak wall adsorption are simulated to elucidate peak distortions. Finite sample injection length/amount and wall adsorption that lead to systematic errors in the estimated binding constants in ACE are quantified for the first time with both actual experiments and computer simulation. Methods for correcting the estimated binding constants are proposed to extend the usefulness of ACE.

DOI10.1021/ac070412r
Alternate JournalAnal. Chem.