The Statistical Evaluation of Migration Parameters of Flavonoids in Capillary Electrophoresis with Reference to Structural Descriptors

Abstract

Under each of 38 buffer conditions, six migration parameters of 14 flavonoids were obtained in capillary zone electrophoresis (CZE) and nine parameters in micellar electrokinetic capillary chromatography (MEKC). A total of 183 structural descriptors for each flavonoid were calculated to represent the molecular structures in a quantitative way. The relationship between the structural descriptors and the migration parameters of flavonoids in CZE or MEKC were evaluated by cluster and factor analyses. Under all CZE conditions the apparent solute mobility (μa) was always the first variable to associate with all molecule-level structural descriptors and the electrotopological state indices (Si) of skeletal carbons, whereas the effective mobility (μe) was closer to Si of oxygens on skeletons. On the other hand, in MEKC retention factor or its logarithm did not depended more on the structural descriptors than other migration parameters. This indicated that the parameter did not represent the properties of the flavonoids better than other parameters. Thus, the results confirmed that hydrophobic interaction was not the only underlying force that influenced the migration behaviour of the flavonoids in MEKC.