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The influence of experimental conditions on chiral separation of borane clusters in capillary electrophoresis
Bodi, Adrián ; Kučera, Radim (advisor) ; Pilařová, Pavla (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of pharmaceutical chemistry and pharmaceutical analysis Candidate: Adrián Bodi Thesis supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: Mgr. Ondřej Horáček Title of thesis: The influence of experimental conditions on chiral separation of borane clusters in capillary electrophoresis Keywords: chiral separation, borane clusters, capillary electrophoresis, cyclodextrins Abstract: Boron compounds also include borane clusters, in which boron atoms form triangular configuration and 30 such sides are presented as a so-called cage. These clusters can be synthetically modified into various forms (open or closed) and can be substitued, for example by carbon atoms. This substitution can lead to the asymmetry of these molecules and thus to their chirality. Currently, their potential is also being studied in medicinal chemistry, where they could contribute to the design of new drugs. For instance, while they are been tested as HIV inhibitors, for boron neutron capture therapy, as CA IX inhibitors, they have also been suitable as part of hydrophobic pharmacophores in the design of drugs targetting the binding sites of various receptors. The task of this thesis is to test the influence of experimental conditions on the chiral separation of...
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Development of electrophoretic method for determination of ethanolamines in antifreeze mixtures
Hamráková, Katarína ; Křížek, Tomáš (advisor) ; Coufal, Pavel (referee)
This bachelor thesis deals with development, optimization and testing of the applicability of electrophoretic method for determination of ethanolamines in antifreeze mixtures. The method was tested with the coolant matrix. For the determination of ethanolamines in antifreeze mixtures a capillary electrophoresis with undirect UV detection was used. Ethanolamines - monoethanolamine, diethanolamine and triethanolamine - are organic compounds, which are used in antifreeze mixtures as corrosion inhibitors because glycols, which are often used in such mixtures, can be, after exposure to high temperatures or oxygen from air, transformed to acids that cause corrosion. The method was optimized by selection of the appropriate composition of background electrolyte, its pH, appropriate ratio of individual buffer components and selection of a suitable internal standard. Background electrolyte was a buffer composed of 60 mM acetic acid and 30 mM histidine, pH 4.59 and lysine was used as an internal standard. Silica capillary with an internal diameter of 50 µm, a total length of 50.0 cm and an effective length of 41.5 cm was used for measurements. Measurement at short end was tested, as well as shortening the capillary to 35.0 cm with an effective length of 26.5 cm, which was further used. The sampling was...
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Determination of low-molecular-mass heparin using affinity capillary electrophoresis
Molnárová, Katarína ; Křížek, Tomáš (advisor) ; Sobotníková, Jana (referee)
Unfractionated heparin, which is a widely used anticoagulant, is frequently replaced with low-molecular-mass species. They are used due to their more predictable anticoagulant effect with less bleeding complications and also they have prolonged anticoagulant effect. For monitoring of low-molecular-mass heparin levels, anti-factor Xa assay is used, which has some significant drawbacks. This work is dedicated to determination of low-molecular-mass heparin, namely Fraxiparine, using affinity capillary electrophoresis. Heparin is a polysaccharide which does not exhibit a significant UV absorption; therefore, its indirect detection method was used. Fraxiparine forms a stable complex with protamine. Protamine is an arginine-rich, positively charged peptide which is used to suppress heparin anticoagulant effect. Because protamine has a complex, not precisely defined structure, it was replaced by well-defined tetraarginine. The method uses phosphoric acid of 9 mmol L-1 concentration with addition of 0.1% (w/v) hydroxyethylcellulose as the background electrolyte. The samples are injected hydrodynamically into the capillary by a pressure of 5 kPa. First, the zone of Fraxiparine was injected, followed by the zone of tetraarginine (5 s). After that, 30 kV voltage was applied for 30 s. During this time the...
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Optimization of electrophoretic determination of protamine and insulin
Molnárová, Katarína ; Křížek, Tomáš (advisor) ; Hraníček, Jakub (referee)
This work deals with optimization of a method for separation and detection of protamine and insulin using capillary zone electrophoresis. The composition of background electrolyte, the solution pH and the injection method were optimized. Citric acid in a concentration range of 80 to 240 mmol L-1 and chloroacetic acid ranging from 50 to 150 mmol L-1 were tested sequentially. The optimized method uses a fused silica capillary with inner diameter of 50 μm. The total length of capillary is 50.0 cm, effective length is 8.5 cm. The injection of the sample is performed on the short end of the capillary. The method uses chloroacetic acid of 100 mmol L-1 concentration as the background electrolyte. Driving voltage is 20 kV. Sample is injected hydrodynamically with a pressure of 5 kPa for 3 s. The analytes are detected spectrophotometrically at wavelength of 200 nm. The method allows for determination in case of protamines in concentration range between 4 μg mL-1 and 300 μg mL-1 and insulin from 5 μg mL-1 to 300 μg mL-1 . The limits of detection are 1 μg mL-1 for protamine and 2 μg mL-1 for insulin. Repeatability of migration times and peak areas tested at 30 μg mL-1 and 200 μg mL-1 concentration levels using hydrodynamic injection showed values of relative standard deviation lower than 6 % suggesting...
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