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Influence of the interacting constituent of the background electrolyte on electrophoretic separation
Müllerová, Ludmila ; Dubský, Pavel (advisor) ; Kašička, Václav (referee) ; Petr, Jan (referee)
Capillary electrophoresis is a widely used separation method of analytical chemistry. Addition of a selector into the background electrolyte extends its applicability to separation of enantiomers or of compounds of similar physicochemical properties. In analytical practice, mixtures of selectors are also commonly used - either prepared intentionally to achieve better separation or because commercially available selectors may be mixtures of compounds differing in the degree of substitution and substituent positions. Mathematical description of these systems, which are highly relevant in analytical practice, can simplify search for optimal separation conditions. Also, it provides a useful insight into the separation mechanism. In this work, a model of electromigration of an analyte interacting with a mixture of two selectors is proposed and experimentally verified. This model results from a more general description of systems with an arbitrary number of selectors. The model shows that a selector mixture can be treated as a single selector if the ratio of the respective selector concentrations is kept constant. When the mixture is prepared intentionally, this description predicts, how separation potential of the mixture changes with its composition. Thus it allows the optimal composition and total...
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Influence of the interacting constituent of the background electrolyte on electrophoretic separation
Müllerová, Ludmila ; Dubský, Pavel (advisor) ; Kašička, Václav (referee) ; Petr, Jan (referee)
Capillary electrophoresis is a widely used separation method of analytical chemistry. Addition of a selector into the background electrolyte extends its applicability to separation of enantiomers or of compounds of similar physicochemical properties. In analytical practice, mixtures of selectors are also commonly used - either prepared intentionally to achieve better separation or because commercially available selectors may be mixtures of compounds differing in the degree of substitution and substituent positions. Mathematical description of these systems, which are highly relevant in analytical practice, can simplify search for optimal separation conditions. Also, it provides a useful insight into the separation mechanism. In this work, a model of electromigration of an analyte interacting with a mixture of two selectors is proposed and experimentally verified. This model results from a more general description of systems with an arbitrary number of selectors. The model shows that a selector mixture can be treated as a single selector if the ratio of the respective selector concentrations is kept constant. When the mixture is prepared intentionally, this description predicts, how separation potential of the mixture changes with its composition. Thus it allows the optimal composition and total...
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System zones in capillary electrophoresis
Riesová, Martina ; Gaš, Bohuslav (advisor) ; Kašička, Václav (referee) ; Gebauer, Petr (referee)
Martina Riesová Abstract of Ph.D. Thesis Capillary electrophoresis is a method of choice in many analytical laboratories for its high separation efficiency, rapidity, low consumption of chemicals and therefore low costs. Inherent to each electrophoretic separation system are system peaks, which can significantly affect or confuse the electrophoretic results. In capillary zone electrophoresis, position of system zones can be predicted easily and reliably by means of prediction software based on a theoretical description of electromigration. However, the prediction of only position of a system zone may not be sufficient for identification of system peaks in obtained electropherograms. Therefore, an existing theoretical model was significantly extended and new version of PeakMaster software (PeakMaster 5.3) was introduced in the framework of this thesis. PeakMaster 5.3 enables to predict not only the positions of system zones, but also their shapes and polarity. Thus, PeakMaster 5.3 improves the prediction possibility of overlapping or interaction of system peaks with analyte peaks. Moreover, composition of the sample can be optimized in order to obtain convenient shapes and amplitudes of system peaks. The applicability of capillary zone electrophoresis can be extended by addition of a complexation agent into...
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