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Comparison conductive detectors for capillary electrophoresis
Kříček, Zdeněk ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
The aim of this bachelor thesis is comparison of two contactless conductivity detectors in capillary electrophoresis. Two methods were used for comparison: The determination of saccharides, namely glucose, fructose and sucrose, and then the determination of inorganic ions, such as chlorides, nitrates, and sulphates. The theoretical part deals with capillary electrophoresis in general and then the specific use of a contactless conductivity detector in capillary electrophoresis and its optimization. Parameters used for comparison of detectors such as limit of detection or relative standard deviation are described. Afterwards, different methods that can be used for the separation and determination of saccharides and inorganic ions are reviewed. The experimental part contains data that were measured in the optimization part of this study as well as comparison of the two detectors used, Admet and TraceDec. The comparison part starts with the method for the separation of saccharides using short-end injection mode in 40mmol∙l−1 sodium hydroxide with a separation voltage of −15 kV. The internal standard was 0,1mg∙ml−1 lactose. The calibration curve was measured in the concentration range from 0,01 to 0,5 mg∙ml−1 The linearity was measured with values of LOD, LLOQ and RSD determined as well. The values of...
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Utilization of ultra-high performance liquid chromatography for simultaneous determination of paracetamol, amoxicillin, and doxycycline
Hrašková, Hana ; Kubíčková, Anna (advisor) ; Sobotníková, Jana (referee)
In this study, a method was developed for the simultaneous determination of three pharmaceutical compounds: amoxicillin, doxycycline, and paracetamol. Ultra-high performance liquid chromatography (UHPLC) was employed for the separation. A Kinetex column C18 measuring 100×2,1 mm with a particle size of 1,7 μm was used as the stationary phase. The optimal method was run in gradient mode with a total analysis time of 5 minutes. The mobile phase consisted of a mixture of component A, containing acetonitrile with 0,1% formic acid, and component B, comprising deionized water with 0,1% formic acid. The separation conditions in the column varied according to the following gradient program: 0 - 1,0 min: 10% A (v/v); 1,0 - 1,5 min: 10% → 65% A (v/v); 1,5 - 2,0 min: 65% A (v/v); 2,0 - 2,5 min 65%→10% A (v/v); 2,5 - 5,0 min 10% A (v/v). The pH of the mobile phase was maintained at 2,8. The flow rate was set at 0,3 ml/min, column temperature was maintained at 25řC, and the autosampler temperature was consistently held at 8řC. The injection volume was 1 μl, and analytes were detected using a diode array detector at a wavelength of 245 nm. Drug identification was conducted using a QDA detector set to positive mode with a mass range from 100,00 to 500,00 Da. The method was partially validated by constructing a...
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Verification of the authenticity of remains of 18th century medicinal products containing juniper or liquorice
Lener, Tomáš ; Nesměrák, Karel (advisor) ; Kubíčková, Anna (referee)
Three remains of historical pharmaceuticals from 18th century containing juniper (Rob juniperi, Lignum juniperi) or liquorice (Pulvis radicis liquiritiae) were analyzed by HPLC-MS method and their authenticity was verified using a chemotaxonomic approach. Current reference material was the source of chemotaxonomic markers and also a raw material for replication of Rob juniperi according to two period recepies. HPLC-MS method provided good results but wasinsufficienttoanalyzeLignumjuniperi.Therefore,GC-MSmethod wasalsousedto analyzethejunipersamplesand it provided sufficient results to prove the authenticity of both juniper samples. HPLC-MS method identified viridiflorin heptoside for the first time in juniper material, for which as well as for five liquorice markers ESI fragmentation spectra weremeasured and theirpossiblefragmentation mechanismwasproposed.Based on theobtained results, thepreparation ofhistorical samplesfrom the mentioned plants can beconfirmed. Key words: HPLC-MS, GC-MS,Chemotaxonomy, Juniper,Liquorice, Tandemmass spectrometry,Viridiflorin
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Characterization and application of zwitterionic stationary phases in HPLC
Machová, Dominika ; Kalíková, Květa (advisor) ; Kubíčková, Anna (referee)
This diploma thesis deals with the characterization and comparison of two zwitterionic stationary phases of SeQuant ZIC-HILIC and Atlantis Premier BEH Z-HILIC columns. Analyses were performed in the hydrophilic interaction liquid chromatography (HILIC) separation mode. The ligand bound to both stationary phases of these columns is identical, sulfoalkylbetaine. The main difference between these stationary phases is in the particles to which the ligands are bound. The type of the particles significantly contributes to different interaction and separation properties of the stationary phases. Firstly, for the basic characterization of these stationary phases, a Tanaka's test was performed. The results of this test showed that the SeQuant ZIC-HILIC column has greater cation-exchange properties than the Atlantis Premier BEH Z-HILIC column, which, has on the other hand greater anion-exchange properties. Both stationary phases showed a higher value of the parameter describing hydrophilicity than hydrophobicity, confirming their polar nature. The properties of the stationary phases were further examined and compared based on the analysis of model analytes. These analytes included a range of small polar analytes, acids, bases, ampholytes, neutral analytes, and their mixtures. Analyses were performed at...
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Climate of a school class at a primary school
Kubíčková, Anna ; Hejlová, Helena (advisor) ; Nekardová, Barbora (referee)
This diploma thesis focuses on the social climate in primary school classrooms. It aims to assess whether classroom teachers have an overview of the social climate in their classes. The thesis is divided into theoretical and practical part. The theoretical part examines the social climate of the classroom and the school. Additionally, it deals with aspects of inclusion and integration in the educational environment, as well as classroom management strategies that influence the classroom social climate. In the practical part, teachers' characteristics of the climate in their class are compared with the results of climate examinations conducted in their classes. The research happened in three classrooms and combined qualitative and quantitative approach. Three instruments were used for data collection: a questionnaire, interviews, and a observation. During the research evaluation phase, the averaged student responses in the questionnaire were compared with the teachers' responses, and data triangulation was performed. The completed questionnaires were compared not only with each other, but with the teachers' characteristic of the classroom climate obtained through interviews and observations as well. The research findings indicate that the teachers' perceptions of the social climate in their...
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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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Development of Electrochemical Thin-layer Degradation Cell for Oxidation Stress Testing of Active Pharmaceutical Ingredients
Šefčík, Martin ; Kubíčková, Anna (advisor) ; Coufal, Pavel (referee)
In this thesis, the oxidation conditions in a new electrochemical "thin-layer" flow-through cell for the study of the oxidative degradation of active pharmaceutical ingredients were optimized. In this field, it is an innovative approach to studying the oxidation properties of substances. The cell was manufactured using 3D printing technology. Oxidation was carried out in a two-electrode arrangement with a working boron-doped diamond electrode (BDDE) and an auxiliary stainless steel electrode. Optimization of conditions was performed using salicylic acid as a model active pharmaceutical ingredient. The electrochemical approach was used to degrade this active pharmaceutical ingredient by the required approximately 20% of the original amount in only 2.3 min. Thus, the degradation time was significantly reduced compared to the oxidative stability stress tests of active pharmaceutical ingredients commonly used today. Two major degradation products were observed, namely gentisic acid and 2,3-dihydroxybenzoic acid. The degradation products obtained by electrochemical oxidation and chemical oxidation using hydrogen peroxide are identical.
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Development of electrochemical flow-through detectors based on carbon nanotubes
Pavlíčková, Eva ; Dejmková, Hana (advisor) ; Kubíčková, Anna (referee)
This work deals with the development of a flow through detection cell using carbon nanotubes deposited on a membrane as the working electrode. 3D printing was used to obtain prototypes of the detection cells. Uric acid and dopamine were used as analytes to verify the functionality of the cells. Three prototype cells were prepared during the work, differing in the location of the reference electrode and in the method of inserting the working electrode. Four cells with different internal dimensions are compared in this work, the best cell is the one with a length of 3 mm and a diameter of 3 mm. This membrane has to be lined with a non-woven fabric and another membrane for lower deformation of the nanotube membrane. The optimum conditions for the determination of the dopamine-urea acid mixture are: mobile phase 90 % phosphate acetate buffer pH 6 and 10 % methanol, input potential 0,5 V and flow rate 0,5 ml/min. The concentration of the nanotubes on the membrane is 0,05 mg/ml, higher concentration does not improve the degree of conversion, which is 0,6. Different types of nanotubes are also compared in this work. The short and wide nanotubes appear to be the best ones, which have the best repeatability and are closest to the theoretical charge exchange value of the measured substances.
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