National Repository of Grey Literature 149 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Determination of selected elements in cereal flours and their gluten-free alternatives
Venclová, Veronika ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
This study deals with the determination of calcium, magnesium, phosphorus, potassium, sodium, iron, zinc, copper, manganese and molybdenum in cereal gluten flours and its gluten-free alternatives. The flour samples were digested using a microwave device and the elements in solution were subsequently determined using an inductively coupled plasma mass spectrometer. Optimization of the digestion of the selected flours was performer prior to the actual determination of the elements. The aim of the work was to determine the above listed elements in the flour samples and to establish a basic overview of the elemental composition of the different flours. This overview and comparison of the different flours is intended to help the people with celiac disease to choose gluten-free alternatives to wheat flour. Keywords Inductively coupled plasma mass spectrometry, microwave digestion, calcium, magnesium, phosphorus, potassium, sodium, iron, zinc, copper, manganese, molybdenum, wheat flour, gluten-free flours, celiac disease
Determination of calcium, magnesium and phosphorus in selected types of animal bones
Škardová, Alice ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
This research focuses on the elemental analysis of selected elements (calcium, magnesium, and phosphorus) within the bones of various animal species, aiming to make comparative nutritional assessments. The obtained bone samples were subjected to mechanical grinding and then quantitatively weighed into collapsible cartridges. Using high-pressure microwave decomposition with the incorporation of nitric and hydrochloric acid, the samples were transformed into solution form, which was then appropriately diluted. The analysis of the liquid samples was carried out using a mass spectrometer with inductively coupled plasma. The observed composition for each sample was calculated using the calibration curve, accounting for both sample mass and dilution factors. All results obtained exceeded the detection limit for calcium 0.38 mg/l, magnesium 0.037 mg/l, and phosphorus 0.078 mg/l. The main finding of this research is the complete understanding of the elemental makeup present within the bones of distinct animal species.
Optimization of the optical setup for chemiluminescence detection of natural products
Laho, Tomáš ; Dian, Juraj (advisor) ; Hraníček, Jakub (referee)
The content of the bachelor thesis was the implementation of a new luminescent apparatus and the study of chemiluminescence of luminol and beer samples of suitable age. The chemiluminescence of luminol was used in this work to determine its basic characteristics (spectrum, intensity of chemiluminescence, and its dependence on the composition of the reaction mixture) using a fiber spectrometer and, subsequently, verify the functionality of the assembled apparatus. This work aimed to realize an apparatus suitable for the chemiluminescence measurement of natural substances with potential use in the food industry. Luminol made it possible to observe intense chemiluminescence, thanks to which it was possible to optimize the measured signal. After successful optimization, there was an attempt to detect the chemiluminescent response in samples of artificially aged beer and compare the results obtained with those already published in the professional literature. In the presented bachelor thesis, the characteristics of luminol chemiluminescence were measured using a fiber spectrometer. Based on these results, the parameters of the new luminescent apparatus (size of slots, voltage on the photomultiplier) and the maximum values of chemiluminescence intensity for the correct operation of the apparatus were...
Reduction of polyatomic interferences in As and Se determination by ICP-MS
Vajnahij, Volodymyr ; Nováková, Eliška (advisor) ; Hraníček, Jakub (referee)
This bachelor thesis was focused on the eliminationof polyatomic interferences in the determination of As and Se using inductively coupled plasma mass spectrometry. For this purpose, the collision-reaction cell technique was employed. The collision-reaction cell was filled with either collision gas or collision-reaction gas, namely pure He and H2, at different flow rates.In the case of the determinationof arsenic,which is monoisotopic and therefore no isotope other than 75 As can be selected, one of the main polyatomic interferences is 40 Ar35 Cl+ , which has the same mass-to-charge ratio m/z = 75 as 75 As. In the case of selenium determination, there are isobaric interferences due to 40 Ar38 Ar+ , 40 Ar40 Ar+ and 38 Ar40 Ca+ affecting the measurement of 78 Se and 80 Se. When 78 Se was determined in the He mode with 5 ml ∙ min-1 , a 300-fold decrease in BEC was observed. At the same time, this collision gas flow rate is higher than the routinely used one and thus able to remove more polyatomic interferences caused by 40 Ar38 Ar+ and 38 Ar40 Ca+ , respectively.Aslight improvement in some parameters was also achieved by using the H2 mode, which is more effective in reducing polyatomic interferences in the determination of Se than the He mode. With the removal of argide interference, H2 reaction...
Development of the UHPLC-PDA method to determine the active substances in the tablet Ataralgin
Chocová, Natálie ; Kozlík, Petr (advisor) ; Hraníček, Jakub (referee)
The Ataralgin tablet is an over-the-counter drug that helps against pain and elevated body temperature. The tablet contains three active substances - paracetamol, caffeine and guaifenesin. The aim of this thesis was to develop a rapid, effective, selective and simple UHPLC-PDA method suitable for the determination of active substances in the Ataralgin tablet which would subsequently serve for quality control during the production of this drug in the pharmaceutical industry. Separation was performed on the Acquity UPLC BEH C18 column (50 × 2.1 mm, 1.7 µm), the column temperature was set at 40 řC, autosampler temperature was 10 řC, the mobile phase was composed of methanol (B) and distilled water with the addition of 0.1% formic acid (A), sample injection volume was 1 µl and the flow of mobile phase was 0.4 ml·min-1 , gradient elution (time: 0-0.5-1.5-2.5-3-5.5 min, A: 85-85-30-30- 85-85% v/v). UV detection at 275 nm and the total analysis time was 5.5 minutes. The trueness (relative error) was in the range of 0.05 - 2.73 % and the accuracy (relative standard deviation) was in the range of 2.38 - 5.79 %. The LOD values were: 9.25·10- 4 mg·ml-1 for paracetamol, 2.15·10-4 mg·ml-1 for caffeine and 7.93·10- 4 mg·ml-1 for guaifenesin and values for the LOQ were 3.08·10-3 mg·ml-1 for paracetamol, 7.17·10-4...
Elemental analysis of dendrochronological Norway spruce sample
Zámečník, Karel ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
The subject of this bachelor's thesis is the determination of lithium, sodium, magnesium, potassium, calcium, manganese, iron, zinc, selenium, rubidium, strontium, cadmium, antimony, cesium, barium, and thallium in dendrochronological samples of Norway spruce using inductively coupled plasma mass spectrometry. The samples of the Norway spruce were collected in the autumn of 2018 on the southern slope of hill Melechov in the Vysočina region. The stem sample was first divided into pieces according to the distance from the bark and labelled A1a to A1g. The ash sample was obtained by burning a cross-section of the stem and separating the bark, from which the A3b sample was created. The remaining two samples were made up of needles and twigs and labelled as samples E and F. For elemental analysis, the samples needed to be converted into a solution, which was achieved by dissolving them in a mixture of hydrochloric, nitric, and hydrofluoric acid, using a microwave digestion device. After dissolution, a solution of boric acid was added to each sample solution to complex any unreacted hydrofluoric acid, which could damage the internal components of the ICP-MS. Calibration solutions were then created with concentrations of 0,0016; 0,008; 0,04; 0,2 and 1,0 mg/l from stock solutions containing the analysed...
Development of a UHPLC-MS/MS method suitable for the determination of cabozantinib in blood serum
Kleinová, Jana ; Kozlík, Petr (advisor) ; Hraníček, Jakub (referee)
The aim of this Bachelor thesis was to develop a UHPLC-MS/MS method for the determination of Cabozantinib in blood serum. This method was used to monitor the release of the active substance in a model organism - the rat. First, the mass spectrometer setup was optimized, where MRM transitions for Cabozantinib and isotope-labelled Cabozantinib-D4 were found. For Cabozantinib, an MRM transition of 502.2 → 323.1 was found with optimal energy levels of Q1 = -26.0 V, CE = -40.0 V and Q2 = -22.0 V. For Cabozantinib-D4, the MRM transition of 506.2 → 327.0 was found with optimal energy levels being Q1 = -26.0 V, CE = -39.0 V and Q2 = -22 V. The method setup parameters were as follows: The chromatography column used was a Poroshell 120 EC-C18, 2.1x50 mm, 1.9 um, (Agilent Technologies). The mobile phase consisted of acetonitrile (B) and formic acid (A), the flow rate of the mobile phase was 0.350 ml/min, the analysis time was 5.5 min and the injection volume was 1 μl at gradient elution (time: 0; 0.5; 2.0; 3.0; 3.5; 4.0; 5.5 min, B: 10; 10; 60; 100; 10; 10 %). The method was linear (weighted regression 1/x2 ) with a regression coefficient equal to 0.9978, showing an excellent linearity of the method. The precision (relative standard deviation) of the method was within 14 %. The accuracy (relative error) was...
Application of (chir)optical analytical methods in the characterization of nonracemic helically chiral aromatics
Vilím, Vojtěch ; Hraníček, Jakub (advisor) ; Dian, Juraj (referee)
This master thesis is focused on preparation and characterization of thin layers for organic electronics forming a binary system, composed of achiral small conductive molecules (TIPS-pentacen) and chiral helicenes with various electronic density of their aromatic scaffold. Using organic electronics is innovative approach to manufacture electronic devices and compensate disadvantages of inorganic materials-based electronics. Induction of chirality into achiral organic electronics brings new possibilities for application in optical spintronics, optical quantum information processing and many others. Key words: thin layer, helicenes, circular dichroism, organic electronics
Comparison of detection cells for chemiluminescent determination of cobalt ions
Dospělová, Veronika ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
In this thesis, a method for the determination of cobalt ions by sequential injection analysis was developed and optimized. The chemiluminescent reaction of luminol was used for the determination of cobalt ions, where its oxidation by hydrogen peroxide is catalysed by cobalt ions in a basic medium. The reaction is accompanied by the emission of radiation in the form of chemiluminescence, which is detected at a peak wavelength of 425 nm. The determination was carried out in several experimental setups with different types of detection cells. For each setup, the measurement conditions were optimized to achieve the highest and at the same time stable signal of the chemiluminescent radiation intensity. Subsequently, under the optimized conditions, the individual calibration dependencies were measured, and the basic measurement characteristics were determined. Based on these characteristics, the most suitable layout and type of detection cell were selected for which interference studies of selected major cations were measured. The developed method was applied to the determination of vitamin B12 samples. The vitamin molecule contains just one cobalt atom, which was released by different types of decomposition prior to determination. Keywords Sequential injection analysis Chemiluminescence Luminol Cobalt...
UV-photochemical generation of volatile species of tellurium and other transition metals
Jeníková, Eva ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee) ; Kanický, Viktor (referee)
This dissertation thesis is focused on UV-photochemical generation of volatile species of tellurium, ruthenium, rhenium and iridium coupled to methods of atomic spectrometry. In the first part, attention was paid to the optimization of parameters of UV-photochemical generation of volatile tellurium species and its application for speciation analysis of Te(IV) and Te(VI) in water samples. UV-photochemical generation was carried out in a UV-photoreactor, which consisted of a low-pressure mercury lamp wrapped with a polytetrafluoroethylene reaction coil that served as a reactor. Atomic absorption spectrometry with a continuum source of radiation and high resolution and atomization in a miniature diffusion flame were used to optimize the conditions of generation, which included the composition of the reaction medium, irradiation time and the addition of transition metals as modifiers. In order to achieve a higher sensitivity of determination, the generator was coupled to a triple quadrupole inductively coupled plasma mass spectrometer. Since efficient UV-photochemical generation of volatile species was achieved only from Te(IV), with no response from Te(VI), the feasibility of this technique for simple "non-chromatographic" speciation analysis was tested and a method for determination of Te(IV) and...

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