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Study of interaction between protamine and heparin and its applicability in capillary electrophoresis
Martínková, Eva ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
Heparin is an acid mixture of glycosaminoglycans with high negative charge density which naturally occurs in human body. Due to its ability to bind antithrombin III and thus accelerate inhibition of thrombin it has anticoagulant effect. This is abundantly used in clinical practice for operations, in case of embolia or heart-attacks. Protamine is a mixture of small basic peptides, which is used in clinical practice as a heparin antidote. The interaction between heparin and protamine is electrostatic and is also used for determination of heparin in human plasma or blood using affinity methods. In my study it was found that if protamine and heparin are mixed in one vial, a complex is formed. Its resulting charge depends on concentration ratio of protamine and heparin. On the other hand, in case the protamine is injected as a sample and heparin is added to background electrolyte as a protein-binding ligand, it is possible to determine heparin from decreasing protamine peak area. Because of the complexity of protamine-heparin interaction, tetraarginine was used as structurally close model of protamine to increase repeatability of measurements. The method for determination of heparin was optimalised. It uses 20 mM or 60 mM ortho-phosphoric acid as background electrolyte, 1 mg/mL solution of tetraarginine...
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Capillary zone electrophoresis determination of protamines
Malý, Michal ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
This work deals with development and optimization of a method for separation and detection of pro- tamines using capillary zone electrophoresis. The developed method uses a fused silica capillary with inner diameter of 50 µm and effective length of 41,5 cm. Driving voltage is 30 kV. Background electrolyte is aque- ous solution of 45 mmol dm−3 phosphoric acid. Analyte is detected spectrophotometrically at wavelength of 200 nm. Sample is injected hydrodynamically. The method allows for determination of protamines in the concentration range between 11 µg ml−1 to 1000 µg ml−1 , limit of detection is 4 µg ml−1 . Viablity of the method has been verified with a real sample of NPH insulin injection. For sufficiently sensitive detection of protamines in NPH insuline it is necessary to prepare the sample in acidic environment. For the pur- poses of this work the sample was acidified by addition of background electrolyte into the sample so that the background electrolyte concentration in the resulting solution of the sample was 18 mmol dm−3 . The main advantage of the method is the rapid analysis, migration time of the analyte is about 2 min. Disadvantage of the method in comparison to alternate methods using CZE or RP-HPLC is the inability to separate individ- ual protamine peptides. This disadvantage...
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Determination of testosterone esters in injectable dosage form by HPLC-DAD
Folprechtová, Denisa ; Kozlík, Petr (advisor) ; Kubíčková, Anna (referee)
Anabolic steroids are currently very controversial issue not only for its therapeutic use but especially because of the illegal abuse in the sport branch. The aim of this thesis was to develop a rapid, selective, effective and simple method of high performance liquid chromatography suitable for the determination of anabolic steroids in injectable dosage form. The analyzed sample of pharmaceutical product Sustamed contained four testosterone esters: testosterone propionate, testosterone phenylpropionate, testosterone isocaproate and testosterone decanoate. Optimized HPLC-DAD conditions suitable for determination of the selected testosterone esters were as follows: core-shell column Poroshell HPH-C18 (3.0 x 100 mm, 2.7 mm), mobile phase consisted of 10mmol/l ammonium acetate, pH 4.5 and acetonitrile, gradient elution was used. The column was thermostated at 50 řC, injection volume was 1 µl, flow rate was set at 1ml/min and UV detection at 240 nm. Total analysis time was 6 minutes. Key words anabolic steroids, testosterone esters, HPLC-DAD
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HPLC study of chemical reactions
Krouská, Hana ; Kubíčková, Anna (advisor) ; Kozlík, Petr (referee)
In this work hydrolysis of phenylisothiocyanate and subsequent decomposition of diphenylthiourea were studied. RP-HPLC with UV detection was selected for monitoring of these reactions. The new method of isocratic elution was developed and mobile phase composition and flow rate were optimized. Hydrolysis of isothiocyanate was studied as a function of pH and reaction temperature. The subsequent decomposition of diphenylthiourea was carried out at 80 řC depending on the pH.
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Determination of enzyme activity of cellobiase using capillary electrophoresis
Velvarská, Romana ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
This thesis deals with optimization of capillary electrophoresis conditions for the separation of unreacted substrate and products (cellobiose, glucose) generated by the enzymatic cleavage of cellotriose with enzyme cellobiase. The optimal separation electrolyte was shown to be a solution containing 30 mmol·dm-3 sodium hydroxide with addition of 1.0 mmol·dm-3 sodium phosphate and 1.0 mmol·dm-3 sodium phosphate dibasic (pH = 12.38). With this separation electrolyte calibration curves and repeatability were measured and the limits of detection and quantification were determined. The relative standard deviations of peak areas ranged up to 6.1 % and they did not exceed 0.2 % for the migration time. Limits of detection were determined in the range from 0.020 to 0.026 mmol·dm-3 and limits of quantification from 0.066 mmol·dm-3 to 0.085 mmol·dm-3 . Subsequently the enzyme reaction was monitored in offline setup. Furthermore, the offline procedure was automated and the relative standard deviation of cellodextrines after 30 minutes of hydrolysis was ranging up to 13.0 % of glucose and cellotriose and 3.0 % cellobiose using this automated method, which makes it suitable for semiquantitative and comparative measurements. The last part of the experiment was to carry out enzymatic reaction in online setup....
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HPLC study of pharmacological coupling reactions
Krouská, Hana ; Kubíčková, Anna (advisor) ; Kozlík, Petr (referee)
In this work decomposition of phenylisothiocyanate in aqueous and methanolic solutions was studied. RP-HPLC with UV detection was chosen to monitor these reactions. A simple method of isocratic elution has been developed. Due to a long total analysis time, it was necessary to develop also gradient elution method. Using these methods degradation rate of phenylisothiocyanate in methanol and in an aqueous solutions were monitored. Time course of decomposition exhibits exponential shape that is typice for the first-order kinetics. The measurements also showed that disintegration of phenylisothiocyanate is slower in water than in methanol. In both cases it is very slow - decomposition of half of the original quantity of phenylisothiocyanate occurs within days.
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Analysis of amino acids and polyamines by HPLC and CZE
Kubíčková, Anna ; Coufal, Pavel (advisor) ; Pacáková, Věra (referee) ; Flieger, Miroslav (referee)
(EN) This work is focused on two specific classes of amines. First group comprises of cyclic polyaminocarboxylates from the DOTA (1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid) family, which are important reaction intermediates in magnetic resonance imaging (MRI) contrast agent synthesis. In the development of new contrast agents, carboxyl groups are very often protected with tert-butyl ester groups. Among these derivatives, tBu3DO3A is of the highest importance. Therefore, reverse-phase high performance liquid chromatographic (RP-HPLC) and non- aqueous capillary zone electrophoretic (CZE) methods were evaluated for qualitative and quantitative analysis of tBu3DO3A (1,4,7,10-tetraazacyclododecan-1,4,7- tris(tert-butylacetate) and two typical reaction by-products, i.e. tBu4DOTA (1,4,7,10- tetraazacyclododecan-1,4,7,10-tetrakis(tert-butylacetate) and tBu2DO2A (1,4,7,10- tetraazacyclododecan-1,4-bis(tert-butylacetate). These optimized methods were successfully applied to monitoring of real reaction mixtures during synthesis of a new MRI contrast agent. No further sample pretreatment was necessary. In the second part of the thesis, proteinogenic amino acids and polyamines were used as model analytes for development of a new post-column solid-phase reactor suitable for on-line derivatization...
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Analysis of amino acids and polyamines by HPLC and CZE
Kubíčková, Anna
(EN) This work is focused on two specific classes of amines. First group comprises of cyclic polyaminocarboxylates from the DOTA (1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid) family, which are important reaction intermediates in magnetic resonance imaging (MRI) contrast agent synthesis. In the development of new contrast agents, carboxyl groups are very often protected with tert-butyl ester groups. Among these derivatives, tBu3DO3A is of the highest importance. Therefore, reverse-phase high performance liquid chromatographic (RP-HPLC) and non- aqueous capillary zone electrophoretic (CZE) methods were evaluated for qualitative and quantitative analysis of tBu3DO3A (1,4,7,10-tetraazacyclododecan-1,4,7- tris(tert-butylacetate) and two typical reaction by-products, i.e. tBu4DOTA (1,4,7,10- tetraazacyclododecan-1,4,7,10-tetrakis(tert-butylacetate) and tBu2DO2A (1,4,7,10- tetraazacyclododecan-1,4-bis(tert-butylacetate). These optimized methods were successfully applied to monitoring of real reaction mixtures during synthesis of a new MRI contrast agent. No further sample pretreatment was necessary. In the second part of the thesis, proteinogenic amino acids and polyamines were used as model analytes for development of a new post-column solid-phase reactor suitable for on-line derivatization...
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Characterization of low-molecular-mass synthetic markers of isoelectric points by capillary zone electrophoresis and capillary isoelectric focusing
Brandejsová, Martina ; Kašička, Václav (advisor) ; Kubíčková, Anna (referee)
High-performance electromigration separation methods, capillary zone electrophoresis (CZE) and capillary isoelectric focusing (CIEF), have been applied to physico-chemical characterization of new synthetic low-molecular mass markers of isoelectric points. Amphoteric compounds on the basis of aminomethylnitrophenols, their derivatives and other structurally related substances were analyzed by CZE in a series of background electrolytes in a wide pH range, 1.86 - 11.18. From the measured pH dependencies of effective electrophoretic mobilities of analytes (beforehand corrected to reference temperature of 25 řC), their isoelectric points (pI) were determined. In addition, using the non-linear regression analysis of the above dependencies, acid-base dissociation constants (pKa) of ionogenic groups of selected analytes were calculated. Subsequently, the analytes with sharply defined isoelectric points were analyzed by CIEF. CIEF confirmed applicability of these compounds as markers of isoelectric points for calibration of pH gradient in CIEF in the determination of pI of amphoteric compounds, especially peptides and proteins. The determined pKa values of ionogenic groups in particular compounds will be utilized in the development of new pI markers with desired pI values.
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The issue of child soldiers in international law with regard to the African regional regulation
Kubíčková, Anna ; Honusková, Věra (advisor) ; Bayerová, Monika (referee)
The main purpose of this thesis was to give a general overview of the problem of child soldiers and their protection among international law conventions and among regional law agreements with the focus on the African continent. The use of child soldiers in armed conflict is qualified as one of the worst forms of child labour.The majority of child soldiers are active in Africa and, to a lesser extent, in the Middle East and Asia. Besides introduction and conclusion, the study consists of five chapters. The first chapter describes the protection of child soldiers on the international level. Therefore it is focused on individual conventions, especially on Geneva Conventions, Additional Protocols to the Geneva Conventions, the Convention on the Rights of the Child, the Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict, the Optional Protocol to the Convention on the Rights of the Child on a Communications Procedure, but as well on the International Labour Convention No. 182 or the Rome Statute. The soft law represents Paris principles. Discussed is particularly the question of the age limit for child participation in armed conflict. The second chapter is concerned with the international control mechanisms, resulting from the above-mentioned...
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