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Determination of total iron content in selected food supplements
Štádlerová, Barbora ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
In this bachelor's thesis a comparison of three analytical methods for total iron determination in three different food supplements is described. The examined food supplements are Biovit C60, Hemofin and Aktiferrin Compositum. The three methods used for determination of iron are manganometric titration, atomic absorption spectrometry and sequential injection analysis paired with spectrophotometric detection. Two methods were used to prepare solutions of each supplement - they were dissolved in distilled water and also prepared by microwave decomposition of samples. The microwave decomposition is definitely a more suitable preparation method in this case, considering the composition of each supplement. The least suitable of all three methods mentioned above has to be the manganometric titration due to the composition of the matrix. The calibration curve was used to determine total iron content by atomic absorption spectrometry with flame atomization. The agent used in sequential injection analysis to create a product, which can be detected by UV/VIS spectrophotometry was 1,10-phenantroline. The final product was red with the absorption maximum at 512 nm. The most accurate results were obtained by atomic absorption spectrometry.
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Electrochemical generation of tellurium volatile compounds with atomic absorption spectrometry
Labancová, Katarína ; Hraníček, Jakub (advisor) ; Jelínek, Ivan (referee)
EN The present diploma thesis deals with the electrochemical generation of volatile tellurium compounds in connection with atomic absorption spectrometry with the main goal to increase the response of the tellurium signals and thus expand the existing knowledge about this element. Tellurium is one of the heavier elements that forms less stable volatile compounds. The reason for choosing these elements was the fact that its concentration increases mainly in landfills where it is released into the environment, which can have an ecological impact and an impact on human health. In the first step, two types of electrochemical cells were constructed - a thin-film flow electrochemical cell with and without an ion exchange membrane and an apparatus with a flow injection arrangement. The choice of cell types, cathode and anode material and apparatus design was chosen based on a literature research. Attention was paid to the optimization of reaction conditions for electrochemical generation of volatile tellurium compounds, which significantly affect the efficiency of generation using a heated quartz tube atomizer. The optimized parameters were electrolyte concentration, carrier gas volume flow rate, electrolyte volume flow rate and generation current. In the second step, the effect of the temperature of the...
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Determination of bismuth using chemical generation volatile compounds technique with AAS detection
Petreňová, Štěpánka ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
EN This bachelor thesis is focused on the optimization method of determination of bismuth using chemical generation volatile compound coupled with AAS detection with quartz tube. As a part of this task carrier gas flow rate, the flow rate of working solutions, the concentration of the working solution and the temperature of the atomizer were optimized. After this, the calibration dependence was measured for samples of bismuth in hydrochloric acid and samples of bismuth in deionized water and the basic characteristics of the methods were established. Last part of this thesis was aimed to study of different interfering elements and compounds such as arsenic, lead, copper, iron, sodium, calcium, sulphate and chloride. Key words Chemical generation, atomic absorption spectrometry, bismuth, flow injection analysis, interferences
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Extraction method for losartan determination in pharmaceutical compounds by sequential injection analysis with UV/VIS and fluorimetric detection
Zimmermannová, Jana ; Rychlovský, Petr (advisor) ; Hraníček, Jakub (referee)
The diploma thesis deals with the extraction method for determination of losartan using sequential injection analysis with spectrophotometric and spectrofluorimetric detection. The principle of determination is based on losartan ion-pair formation with the orange II and calmagite dyes in an acid buffer, which is then extracted into a chloroform phase. For the purposes of the analytical determination of losartan, an increase in absorbance and fluorescence emission of the ion-pair extracted into the chloroform in its absorption maximum is detected. Losartan potassium was used as the standard substance. First, the conditions for determination in a static arrangement with UV/VIS detection were verified and the basic optimization parameters of determination were measured and the basic characteristics of the determination were identified in the first part of the thesis. An SIA extraction apparatus was prepared and the control programme for the entire analytical process was created in the other part of the thesis. Then the experimental parameters of the determination were optimized and the basic characteristics for both spectrophotometric and spectrofluorimetric detection were measured. The reliability of the losartan determination using the selected methods was verified by analysing real pharmaceutical...
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Comparison of basic analytical characteristics of determination for each species of selenium in the chemical and electrochemical hydride generation of selenium species with AFS detection
Šáriczká, Michaela ; Rychlovský, Petr (advisor) ; Hraníček, Jakub (referee)
This thesis deals with the further development of the technique of generation of volatile compounds as derivatization methods by speciation analysis of selenium compounds. Specifically, this diploma thesis compares technique chemical and electrochemical generation of selected species of selenium (inorganic Se (IV) inorganic Se (VI), selenomethionine (Se- Met), selenocysteine (Se-Cys), methyl-selenocysteine (Met-Se-Cys) and seleno-urea (Se-U)). The achieved basic analytical characteristics are compared of each species in non-column arrangement with atomic fluorescence spectrometry. The effect of pre- reduction/decomposition unit are tested, using the pre-reduction agent KBr and hydrochloric acid at higher temperature and in the presence of UV radiation. Keywords Selenium, speciation analysis, chemical hydride generation, electrochemical hydride generation, atomic fluorescence spectrometry
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Determination of vitamin B12 by flow analysis with chemiluminiscent detection
Svobodová, Kateřina ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
This thesis reports determination of vitamin B12 by flow techniques of analysis. This method is based on luminol-peroxide chemiluminiscence assay for the detection of cobalt (II) ions in vitamin B12 molecules. The method includes releasing of Co2+ from the vitamin B12 using different types of its decomposition; these are mentioned in this thesis. The efficiency of the decomposition of real samples of vitamin B12 in this study reached 74.43 %. The high efficiency was achieved with 1.5 mmol.l-1 K2S2O8 and irradiation time 1 minute. In the FIA mode, the linear range obtained was between 1.0 to 500 mg.l-1 with a relative standard deviation (RSD) 2.59% (n = 10), limit of detection (LOD) 55 µg.l-1 . The minimum sample volume required and the time of analysis were 60 µl and 140.2 s. In the SIA mode, the linear range obtained was between 0.01 to 50 mg.l-1 with an RSD = 4.5% (n = 10), LOD = 25 µg.l-1 . The minimum sample volume required and the time of analysis were 250 µl and 80.1 s. Interference study showed that from wide range of interfering ions were selected only Ni2+ , Zn2+ and NO2 - , that from concentration level 50 mg.l-1 they significantly affect the determination of the Co2+ in solution. The intensity of chemiluminiscence most suppress ion Zn2+ . The solution with the concentration ratio of Co2+...
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Determination of cadmium and copper in bood of great tits
Adamová, Simona ; Hraníček, Jakub (advisor) ; Červený, Václav (referee)
EN Monitoring of the environment is one of the most important activities nowadays. This monitoring includes, for example, monitoring the concentration levels of heavy metals in organisms with a defined relationship to the environment. Great tit (Parus major) was evaluated as a suitable indicator of the environment especially for its abundance and presence near human settlements. The target of this bachelor thesis is to determine cadmium and copper in dried blood samples of these birds from several parts of Europe. All samples were prepared using microwave digestion and analyzed using the inductively coupled plasma mass spectrometry, which is known for its ability to determine simultaneously metals in biological samples even at very low concentrations. Key words Inductively coupled plasma mass spectrometry, heavy metals, copper, cadmium, great tit, blood
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Determination of zinc in food supplements
Nedorostová, Helena ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
- 1 - Abstrakt Tato bakalářská práce je zaměřena na stanovení zinku (zinečnatých iontů) v potravinových doplňcích pomocí atomové absorpční spektrometrie. Součástí práce je také porovnání mezí detekce dvou odlišných atomových spektrometrů. Cílem práce bylo zjistit optimální podmínky a vliv interferencí na stanovení zinku, nalézt vhodnou metodu pro převedení vzorku do roztoku, a také porovnat meze detekce u použitých přístrojů. Optimalizovanými parametry byla výška paprsku nad hranou hořáku, průtoková rychlost acetylenu, otočení hořáku, šířka spektrálního intervalu, typ plamene. Převedení pevného vzorku do roztoku bylo provedeno ve vodě za laboratorní i zvýšené teploty, v kyselině dusičné nebo kyselině dusičné s přídavkem peroxidu vodíku, též za zvýšené teploty. Analyzovány byly tyto potravinové doplňky: Centrum od A až po železo, Walmark- vápník, hořčík, zinek, Spektrum 50+, Calibrum 50 plus, Supradyn Energy Complex. Množství zinku v potravinových doplňcích bylo stanoveno na spektrometru GBC 933 AA v kolmém uspořádání. K porovnání meze detekce byly použity přístroje GBC 933 AA s výbojkou s dutou katodou a ContrAA 700 s xenonovou výbojkou. U obou přístrojů byl pro experiment použit plamen obsahující acetylen-vzduch. Pro stanovení zinku byla pomocí standardních roztoků vytvořena kalibrační křivka, z níž byly...
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Comparison of selenium extraction efficiency from food supplements
Molnárová, Lucia ; Hraníček, Jakub (advisor) ; Červený, Václav (referee)
The aim of this bachelor thesis was comparison of selenium extraction efficiency from food supplements which contain various declared forms of selenium. The method of atomic absorption spectrometry with flame atomization was used to determine the efficiency of the extraction. The first step for the determination of selenium in four real samples was the experimental finding of optimal conditions for selenium determination by flame AAS technique. Optimized parameters included the flame composition, the fuel flow rate, the angle of burner rotation, the horizontal burner position and the spectral range. During the testing the flame composition, higher responses were measured by using air as an oxidant, and therefore acetylene-air flame was used to other optimize and measure real samples. After optimization of the conditions, the calibration dependence was determined and the basic characteristics of the measurements were calculated. The detection limit and determination repeatability, sensitivity and operating range were determined for selenium determination. The detection limit was 0.12 mg dm-3 . The real samples of the food supplement tablets were mechanically homogenized and transferred to aqueous solutions, which were subsequently analyzed by the optimal conditions. The highest extraction efficiency...
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Determination of Te(IV) by photochemical generation of volatile compounds with atomic spectrometric detection
Ruxová, Helena ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
This thesis deals with the development of a method suitable for determination Te(IV) by UV-photochemical generation of volatile compounds (UV-PVG) in liquid samples. Atomic absorption spectrometry (AAS) and atomic fluorescent spectrometry (AFS) were used as detection methods. The basis of the apparatus for UV-PVG was a mercury lamp wrapped by PTFE capillary. Firstly, the experimental parameters were optimized for both methods. The optimized parameters were the type, concentration, pH and flow rate of the reaction medium, the length of the PTFE reaction coil, carrier gas flow rate (argon), supportive gas flow rate (hydrogen) and atomization temperature. The figures of merit with both detection methods were determined and compared after the method was optimized. Detection limits achieved for these two detection methods were 6,0 µg dm-3 for AFS and 1,50 µg dm-3 for AAS. Performed interference study confirmed a significant effect of many cations of transition metals and hydride forming elements on tellurium determination. The influence of nitric acid in the sample was studied separately. The suitability of the method for tellurium determination was confirmed by using a spiked certified reference material.
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