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Shielding and detection of neutrons
Černý, Tomáš ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
The master’s thesis provides an overview of available neutron sources in terms of neutron yields and energy spectrum of emitted neutrons. Reactions of neutrons with matter, especially neutron scattering and radiation capture, are described. The possibilities neutron neutron detection and spectrometry are also described. The following experiment deals with a design of suitable shielding materials and the analysis of the moderated energy spectrum of neutron flux. The properties of the neutron field were measured using detection by activation. Subsequently, a simulation of the problem was performer in the MCNP program. In the end, the achieved results are compared and evaluated.
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Analysis of Historical Pharmaceutical Preparations Containing Alkaloids, Sulphonamide, Derivatives of Barbituric Acid, and Derivative of Pyrazolone
Kudláček, Karel ; Nesměrák, Karel (advisor) ; Bosáková, Zuzana (referee)
Pharmaceutical preparations of quinine (injection solutions), sulfanilamide, aminophenazone, barbital (tablets), caffeine, phenobarbital (dragee), and theophylline (suppositories) about seventy years old were analyzed using RP-HPLC. Samples were quantified by HPLC-UV and UV-spectrophotometry. Products of degradation were identified using HPLC-UV and HPLC-MS. Conditions of separation were optimized. The samples of quinine injection solutions consist of 92% or 87% of declared quinine content. Quinotoxine has been identified as the product of quinine degradation. The quantification of theophylline in suppositories and caffeine in dragee did not show any degradation after more than 67 years from their manufacturing. Decrase of potent amount (decrase about 8-22 %) were found in drugs containing sulfanilamide, barbital, phenobarbital and aminophenazone. Products of degradation of these pharmaceuticals were not found.
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A novel AAS atomizer based on a dielectric barrier plasma discharge
Novák, Petr ; Kratzer, Jan (advisor) ; Kanický, Viktor (referee)
Atomization of arsine in a novel hydride atomizer for atomic absorption spectrometry (HG-AAS) was thoroughly optimized. This plasma atomizer is based on a dielectric barrier discharge (DBD). Sensitivity and detection limit reached 0.48 s ng-1 As and 0.16 ng ml-1 As, respectively, under optimum atomization conditions (Ar discharge using a flow rate of 60 ml min-1 Ar, DBD power 17 W). Analytical figures of merit reached in DBD are comparable to those found in an externally heated quartz tube multiatomizer (MMQTA) that was chosen as a model of conventional approach to hydride atomization in HG-AAS. An extent of interferences (Se, Sb, Bi) during As determination was investigated comparing both MMQTA and DBD atomizers. The later one was found to be more resistant towards interferences. A simple preconcentration of As in a DBD atomizer was reached after oxygen introduction into the Ar plasma in the DBD resulting in analyte retention in the atomizer followed by its volatilization once the oxygen flow is switched off. Preconcentration efficiency of 100 % was reached and detection limit improvement by a factor of ten was achieved (0.01 ng ml-1 As, preconcentration period 300 s).
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Quantitative Structure-Retention Relationships of Salicylthioamide Derivatives
Kalužíková, Aneta ; Nesměrák, Karel (advisor) ; Sobotníková, Jana (referee)
The aim of the thesis is to study the relationship between the structure of N-benzylsalicylthioamide derivatives and their retention behavior in high-pressure liquid chromatography. Furthermore, the influence of various substituents on electron absorption spectra in ultraviolet spectral range was studied. All studied derivatives have two absorption maxima in ultraviolet spectral range at 260 nm and 293 nm. The substitution of an auxochrome on the acyl ring leads to bathrochromic shift and hyperchromic shift, especially of the first absorption maxima. The presence of an auxochrome on the amide ring leads to hyperchromic shift as well. HPLC reversed-phase chromatography, using XDB-C18 ZORBAX column and mobile phase with various composition of acetonitrile, was used to obtain retention times of the derivatives. Using this data, the correlation equations between retention factor (mobile phase with no acetonitrile), resp. slope of the dependence of the logarithm of retention factor on the volume fracture of acetonitrile in mobile phase, and partition coefficient octanol-water, resp. hydrophobic substituent constants, were derived. Key words: QSAR, HPLC, spectrometry, benzylsalicylthioamides
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Interactions between Schistosoma spp. and their hosts at the metabolome level
Kurečka, Martin ; Kameník, Zdeněk (advisor) ; Mikeš, Libor (referee)
The blood flukes of the genus Schistosoma are important parasites that cause serious chronic diseases in mammals, including humans, in tropical and subtropical countries. Treatment of these diseases is challenging; therefore, new molecular targets are still being sought for the development of vaccines and more effective drugs. To achieve this, better understanding of interactions between the parasite and the host at the molecular level is an important prerequisite. These processes can be studied by quantitative and qualitative determination of metabolite differences in healthy and infected individuals using metabolomics. The work represents a review of low molecular weight substances in tissues and body fluids of schistosome hosts, in which a change in concentration of metabolites putatively related to the infection was observed. Only metabolites with a hypothetical or known mechanism of these changes in the context of infection are covered. The thesis also includes a brief overview of basic methods of analytical chemistry, which are used in studies based on metabolomics. Key words: Schistosoma spp.; intermediate host; definitive host; spectrometry; metabolomics; low molecular compounds
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Shielding and detection of neutrons
Černý, Tomáš ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
The master’s thesis provides an overview of available neutron sources in terms of neutron yields and energy spectrum of emitted neutrons. Reactions of neutrons with matter, especially neutron scattering and radiation capture, are described. The possibilities neutron neutron detection and spectrometry are also described. The following experiment deals with a design of suitable shielding materials and the analysis of the moderated energy spectrum of neutron flux. The properties of the neutron field were measured using detection by activation. Subsequently, a simulation of the problem was performer in the MCNP program. In the end, the achieved results are compared and evaluated.
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Comparison of Calibration Methods for Determination of Quinine in Beverages
Handlová, Zuzana ; Nesměrák, Karel (advisor) ; Kozlík, Petr (referee)
The aim of this bachelor thesis is to compare three calibration methods used for determination of quinine in beverages performed by two instrumental methods. As the calibration methods, calibration curve method, standard addition method and spike were chosen. As the instrumental methods, UV spectrometry and RP-HPLC with UV and fluorescence detection were chosen. The calibration methods were compared in terms of accuracy, precision, and time consumption. The instrumental methods were compared in terms of accuracy. Five different tonic waters were chosen as authentic samples. The most precise results were provided by the calibration curve method. In terms of accuracy it was not possible to determine the most accurate calibration method. Spike was the least time-consuming calibration method. HPLC was more accurate compared to spectrometry. Key words: analytical calibration, spectrometry, high performance liquid chromatography, quinine
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