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Optimization of atomization conditions for bismut, lead and tellurium hydrides for development of hydride atomizers.
Štádlerová, Barbora ; Hraníček, Jakub (advisor) ; Spěváčková, Věra (referee)
This Master thesis is a part of a project: Hydride atomizers for atomic absorption and atomic fluorescence spectrometry - new horizons (GA ČR, P206/17-04329S, principal investigator: prof. RNDr. Jiří Dědina, CSc. DSc.) of which the general target is to make a leap towards the ideal hydride atomizer by optimization of atomization based on the knowledge of the distribution of free atoms and hydrogen radicals inside the atomizers. This thesis contributes to the project by optimizing the atomization parameters for atomic absorption spectrometry with hydride generation. The atomization parameters were optimized for three different types of atomizers - multiatomizer, diffusion flame and "flame-in-gas-shield" atomizer using three different analytes - bismuth, lead and tin. Optimal atomization parameters were found for each of the atomizer and each of the analyte - carrier gas flow and flow of other gases if needed for the analysis. Calibration curves and analytical figures of merit such as sensitivity, LOD and LOQ were estimated. Final comparison is based on the data obtained from calibration curves. MDF and FIGS atomizers are mostly used with AFS detection and they provide lower sensitivity and higher detection limits with AAS detection in comparison with MMQTA. Since the analytes are known to trap...
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Analysis of nanopartical systems by atomic spectrometry
Jeníková, Eva ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
EN The present diploma thesis is focused on optimization methods of titanium and phosphorus concentration for their use in the colloidal solution of TiO2 nanoparticles modified by bisphosphonates. For these analyses was used atomic absorption spectrometry with flame and electrothermal atomization. The characteristics of the two analytes were compared to two different spectrometers. Using the F-AAS technique on the GBC 933 AA spectrometer has been achieved a detection limit of 5,2 mg l-1 for titanium and a detection limit of 163 mg l-1 for the phosphorus. Using the ContrAA 700 spectrometer, F-AAS has been achieved an almost five times lower detection limit of 1,1 mg l-1 for titanium determination. For determination of phosphorus using this spectrometer, was obtained a similar value of 151 mg l-1 , as using the GBC 933 AA spectrometer. The determination of phosphorus by the ET-AAS technique using the ContrAA 700 spectrometer resulted in a detection limit of 1,23 mg l-1 , which is a significant difference compared to the flame system. It has been proved that optimized methods are consistent with the intention, which was confirmed by the analysis of real titanium and phosphorus samples in the colloidal solution of TiO2 nanoparticles modified bisphosphonates.
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Arsenic speciation analysis by hydride generation - cryotrapping - gas chromatography - atomic absorption spectrometry
Petreňová, Štěpánka ; Svoboda, Milan (advisor) ; Šucmanová, Marcela (referee)
EN The thesis is focused on a speciation analysis of arsenic with use of the hydride generation - cryotrapping - gas chromatography - atomic absorption spectrometry. The aim of this project was the development of a method and instrumentation of the speciation analysis of arsenic based on combination of selective generation of substituted hydrides with a detection by atomic absorption spectrometry and with use of the cryotrapping of generated arsenic species and their separation by the gas chromatography. In the first part of this work the effects of individual parameters which influence the separation in the gas chromatograph were studied. Especially, time of injection from the cryotrap into GC, temperature program, carrier gas flow and carrier gas flow through a "deanswitch". Optimization of these parameters is an attempt to achieve a satisfactory resolution of the individual peaks of arsenic species separated by gas chromatography. Furthermore, an adequate sensitivity of this method is required to be achieved in comparison to other methods that use AAS detection such as a combination of hydride generation with cryotrapping. For this reason, the detection limits and the quantification of arsenic species were important to be determined as well. A sampling coil was replaced by a sampling tip...
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UV-photochemical generation of volatile compounds of selenium and tellurium
Nováková, Eliška ; Hraníček, Jakub (advisor) ; Komárek, Josef (referee) ; Šíma, Jan (referee)
The presented thesis deals with UV-photochemical generation of volatile compounds of Se and Te from various species. The aim of the project was to expand the current state of knowledge by the application of photocatalytic reduction of higher oxidation states of Se and Te for the speciation analysis based on UV-photochemical generation of volatile compounds. The first step of the study was the assembly of the apparatus for the photocatalysed UV-photochemical generation of volatile compounds. The material of reactor and the whole experimental set-up were based on literature survey and previous research done in our research group. Experiments were directed towards finding the optimum conditions for generation of volatile compounds of selected model elements Se and Te. Se was studied as the element most commonly determined by the UV-photochemical generation of volatile compounds. Conversely, Te was selected as a model analyte representing elements forming less stable volatile compounds. The second part was the application of the optimised method of photocatalysed UV- photochemical generation of volatile Se compound to the determination of Se in water matrices, liquid certified reference materials and also samples of dietary supplements. TiO2/UV-photochemical generation was also successfully modified to...
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Determination of selected trace elements in cosmetic products using solid sampling GF-AAS
Migašová, Michaela ; Petry-Podgórska, Inga (advisor) ; Červený, Václav (referee)
U N IV E R Z IT A K A R LO V A P ř í r o d o v ě d e c k á f a k u l t a Studijní program: Klinická a toxikologická analýza Michaela Migašová STANOVENÍ VYBRANÝCH STOPOVÝCH PRVKŮ V KOSMETICKÝCH VÝROBCÍCH POMOCÍ SOLID SAMPLING GF-AAS Determination of selected trace elements in cosmetic products using solid sampling GF-AAS B a k a l á ř s k á p r á c e Vedoucí bakalářské práce: Dr. Inga Petry-Podgórska Praha, 2017 Prohlášení Prohlašuji, že jsem tuto závěrečnou práci zpracovala samostatně, a že jsem uvedla všechny použité informační zdroje a literaturu. Tato práce, ani její podstatná část, nebyla předložena k získání jiného nebo stejného akademického titulu. V Praze, 28. srpna 2017 ……………… podpis Poděkování Chtěla bych nejvíce poděkovat mé školitelce Dr. Inze Petry-Podgórske za neskutečnou trpělivost a čas, který mi během měření věnovala a za její cenné rady, které mi poskytla. Dále bych chtěla poděkovat panu RNDr. Jakubovi Hraníčkovi, Ph.D. a RNDr. Stanislavu Musilovi, Ph.D. za pomoc při komplikacích s přístrojem. Poděkování také patří mým rodičům za možnost studia na vysoké škole. Abstrakt Anorganická barviva jsou využívána při výrobě barevných laků na nehty. Pigmenty jsou nejčastěji složeny ze sloučenin přechodných kovů. Úkolem této bakalářské práce byla optimalizace podmínek pro stanovení olova ve vybraných...
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Arsenic determination in beer samples and raw materials for its preparation
Švadlenová, Veronika ; Hraníček, Jakub (advisor) ; Jelínek, Ivan (referee)
This thesis describes the optimization of the method for determination of arsenic by the chemical hydride generation coupled with AAS detection in beer samples and raw materials for its preparation. The beer usually contain arsenic at ultratrace level, however, it is necessary to monitor the concentration of this element in the beer. The routinely used method for determination of arsenic is determination by electrothermal atomization. This approach is time consuming, expensive and less sensitive. It has been developer suitable determination of arsenic as a faster and less expensive method. For this method there was optimized the flow rate of argon to 75 ml·min-1, the optimum flow rate for the reagents was 4.0 ml·min-1 and for the sample 5.0 ml·min-1 . 3 % NaBH4 in 0.5 % NaOH was used as the reducing agent for the determination of arsenic, and HCl diluted 1:1 with distilled water was used to acidify the sample. With this parameter LOD was 0.32 μg·l-1 and LOQ 1.05 μg·l-1 . It has been tested the arsenic determination in samples of barley, malt and potable water as beer raw materials. It has been found that the beer matrix is unsuitable for the hydride generation technique due to a stormy reaction in the gas/liquid phase separator. The effect of pretreatment, which is likely to enhance the effect of...
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Determination of magnesium in food supplements by atomic spectrometry techniques
Tomášková, Sabina ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
Tato bakalářská práce je zaměřena na stanovení hořčíku v běžně dostupných potravinových doplňcích pomocí vybraných spektrometrických analytických metod - atomová absorpční spektrometrie a atomová emisní spektrometrie. Analyzovány byly následující potravinové doplňky: Calibrum 50 Plus, Centrum s multi-efektem, Magnesii lactici, Spektrum 50+, Supradyn a Hemofin. V rámci této práce byla nalezena vhodná úprava vzorků pro jejich převedení do roztoku, dále u obou metod byly nalezeny optimální podmínky pro stanovení hořčíku. Optimalizovanými parametry byla výška paprsku nad hranou hořáku, průtoková rychlost paliva, šířka spektrálního intervalu a poloha hořáku. Pomocí atomové absorpční spektrometrie byl hořčík stanoven v plameni acetylen-vzduch. Pomocí atomové emisní spektrometrie byl hořčík stanoven v plameni acetylen-oxid dusný. Meze stanovitelnosti se pohybovaly pro uvedené metody následovně: 6,11 µg/l (69,5 µg/l) pro polohu hořáku 0ř (90ř) v případě atomové absorpční spektrometrie a 64,8 µg/l v případě atomové emisní spektrometrie pro polohu hořáku 0ř. V případě obou měření byly provedeny dva způsoby stanovení. V prvním případě byly měřeny roztoky standardů a vzorků bez přídavku pomocných činidel pro potlačení interferencí. V druhém případě již byla přidána pomocná činidla do roztoků standardů i...
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