E-mail | SIS | Moodle | Helpdesk | Libraries | cuni.cz | CIS More

česky | english Log in

Scientific interests

Mgr. Pavel Dubský, Ph.D.

Capillary electrophoresis

Electromigration separation techniques belong to the most effective separation methods in analytical chemistry. Capillary zone electrophoresis is the primary electromigration separation technique. In its various modes (e.g. zone electrophoresis, isotachophoresis, electrokinetic chromatography, isoelectric focusing, on-column chemical reactions, etc.), capillary zone electrophoresis has been providing solutions in several fields of science and technology.

Electrophoresis finds its applications in identification and quantification of inorganic ions, organic compounds used in agrochemistry, food chemistry or pharmacology, as well as the analysis of complex biomolecules such as proteins up to the DNA.


Electrokinetic chromatography & Chiral separations

Electrokinetic chromatography (EKC) is one of the modes of the capillary zone electrohoresis. In this mode, a selector is added into the background electrolyte in which the electrokinetic separation occurs. Micelles and cyclodextrins are the most common selectors used. The selector alters the electrophoretic mobility of the analyte. In this way, it mediates an analysis of analytes with higly similar electrophoretic mobilities, or those without their own electrophoretic mobility (e.i. neutral compounds).

If the selector provides a chiral recognition, it makes the EKC mode well applicable to chiral separations. The identification and quantification of chiral compounds is of high interest in practice. In spite of the undifferentiable 2D structures of the two enantiomers of a chiral compound, their 3D structure gives them inherently diverse biological and pharmacological impacts.


Physical-chemical measurements

Electrophorestic mobility and dissociation constants of the various ionic forms of an analyte are its very basic physical-chemical properties that determine its electromigration. So are the related complexation constants, and mobilities and dissociation constants of the analyte-selector complexes in EKC. If the analyte undergoes a chemical reaction, the reaction rate constant can be determined by dynamic capillary electrophoresis in some cases. A particular example is the determination of rate constants of interconversion of a chiral analyte in both free and complexed forms in dynamic chiral EKC.

The determined physical-chemical paramaters give us information about the studied compounds and their interaction with selectors. Additionally, once measured, the parameters can be reutilised for intelligent method optimisation for complex mixtures of analytes.


Mathematical descrition of the studied systems

Detailed knowledge of the phycal lows that govern electromigration is indisputably the biggest advantage of electromigration separation techniques. Even in the most complex separation systems, the electromigration is completely described by a common set of partial differential equations describing the mass- and charge-conservative ionic fluxes in the electric field, and this set of equations is coupled with yet another set of algebraic equations describing acido-basic (and other chemical) equilibria.

Mathematical analysis of the governing equations leads to the generalised conclusions about the electrophoretic motion in its various modes. Numerical solution of the equations, involving computer simulations, additionaly provides a detail insight into the electromigration processes. Both the mathematical analysis and computer simulations help in designing novel electromigration separation strategies. Just as helpful are they for analytical method deveopment and optimisation of separation conditions.


Software development

As an inevitable part of the research, the mathematical models are implemented in suitable software tools.The modern C++ programming language guarantees good source code maintanance without any lost of the resulting machine code performance. User-friendliness is just as much important aspect of software design&development. User-friendly graphical interface turns the software from a one-purpose home-made solution to a real scientific tool being appretiated by the wider scientific community. 

The software can be downloaded as freeware from the group of Electromigration and Chromatographic Separation Methods


Document Actions