Premium
The effects of a mixture of charged and neutral additives on analyte migration behavior in capillary electrophoresis
Author(s) -
Kranack Andrea R.,
Bowser Michael T.,
BritzMckibbin Philip,
Chen David D. Y.
Publication year - 1998
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.1150190305
Subject(s) - analyte , capillary electrophoresis , chemistry , electrophoresis , cyclodextrin , ether , chromatography , binding constant , phenol , analytical chemistry (journal) , organic chemistry , binding site , biochemistry
Multicomponent additives, such as derivatized cyclodextrins with various degrees of substitution, can be considered single‐component additives as long as the fraction of each component remains constant. In this paper, equations are derived describing the effect of such additives on the migration behavior of analytes. These equations are used in the study of capillary electrophoresis (CE) systems with differentially charged cyclodextrins as additives. For weakly acidic analytes, the binding with highly negatively charged sulfobutyl ether β‐cyclodextrin (SBE‐β‐CD) increases their negative electrophoretic mobility, while the binding with neutral hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) decreases their negative mobility. By obtaining the equilibrium constants and mobilities for each additive with each analyte (in this case, phenol, 2‐naphthol and 1‐naphthol), the migration behavior of these analytes in CE systems is quantitatively predicted at various concentrations of mixtures of the two additives. The properties of the contour lines in the binding isotherm surfaces of such CE systems are discussed.