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Determination of Titanium and Phosphorus by Atomic Absorption Spectrometry
Jeníková, Eva ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
Předkládaná bakalářská práce se zabývá optimalizací metod stanovení titanu a fosforu technikou atomové absorpční spektrometrie s plamenovou atomizací ve složení acetylen-oxid dusný. Pro jednotlivá stanovení byly experimentálně nalezeny optimální hodnoty pro průtokovou rychlost acetylenu, koncentraci přídavku hliníku či vápníku, výšku paprsku nad hranou hořáku a jiné faktory pro zvýšení analytického signálu. Za těchto experimentálně zjištěných podmínek bylo provedeno stanovení a zjištění základní charakteristiky metod u obou prvků. Významnost stanovení těchto dvou prvků souvisí s tím, že materiály na bázi titanu a oxidu titaničitého povrchově modifikované sloučeninami fosforu jsou perspektivní pro řadu biomedicínských i průmyslových aplikací. Powered by TCPDF (www.tcpdf.org)
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Determination of selected elements in plant extracts by atomic absorption spectrometry
Rydlová, Lenka ; Hraníček, Jakub (advisor) ; Kratzer, Jan (referee)
The aim of this bachelor thesis was to determine selected elements (Na, Mg, K, Ca, Zn, Se) in plant extracts and juices by atomic absorption spectrometry using different types of atomization. Each method has been optimized for determination of the mentioned elements. For flame atomization it has been used optimization of height of the primary radiation from the hollow cathode lamp over the edge of the burner. The height was generally between 6.0 and 8.0 mm. Then there have been optimized flow of each component of the flame (acetylene, air, nitrous oxide) and it has been set location of the hollow cathode lamp and the flame. Under the optimized conditions basic characteristics describing the method of the determination of mentioned elements have been measured (LOD for sodium 2.13 µg L-1 , for magnesium 2.44 µg L-1 , for potassium 11.3 µg L-1 , for calcium 15.6 µg L-1 , for zinc 6.04 µg L-1 , for selenium 0.34 µg L-1 ). In the next part of the thesis the optimized methods have been used for measuring concentration of all elements in real samples. After the preparation of the samples including dilution, addition of various reagents etc., they have been atomized by flame in an atomic absorption spectrometer (Na, Mg, K, Ca, Zn) and determined, or converted to a volatile compound (Se) and determined by...
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Determination of Arsenic Using UV-photochemical Generation of the Volatile Species in Formic Acid Medium with AAS Detection
Vlčková, Anna ; Červený, Václav (advisor) ; Hraníček, Jakub (referee)
V této bakalářské práci byla nejprve sestavena aparatura pro stanovení arsenu pomocí UV-fotochemického generování jeho těkavé sloučeniny s AAS detekcí a byly optimalizovány experimentální podmínky navrhované metody. Klíčovými parametry byly: délka reakční cívky ozařované UV světlem; místo zavádění reakčního plynu (vodíku) před UV-fotoreaktor a nosného plynu (argonu) před UV-fotoreaktor a do separátoru fází a jejich průtoky; koncentrace kyseliny mravenčí v nosném roztoku a jeho průtoková rychlost a velikost dávkovaného objemu vzorku. Za optimálních podmínek navrhované metody byla naměřena kalibrační závislost. Pro porovnání výsledků bylo použito stanovení arsenu pomocí chemického generování jeho hydridu. Z porovnání těchto metod vychází chemické generování jednoznačně jako metoda citlivější, protože lze stanovovat koncentrace již od 5,7 ppb As, zatímco metodou UV-fotochemického generování lze stanovovat koncentrace až od 150 ppb As. Za stávajících podmínek je UV-fotochemické generování těkavých sloučenin z důvodu velmi nízké citlivosti (přibližně 16,5 % oproti chemickému generování) pro stanovení arsenu nevhodné.
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Interference study for lead determination using hydride generation technique coupled with AAS detection
Hillmich, Ondřej ; Hraníček, Jakub (advisor) ; Musil, Stanislav (referee)
This bachelor thesis is focused on the interference study of different elements during lead determination using hydride generation technique. For this method tetrahydroborate was used as a reduction agent and hexacyanoferrate as an oxidant agent which dramatically increases efficiency of plumbane formation. Before interference study, significant experimental conditions were optimized. The optimizations include flow rate of carrier gas (argon), concentrations and flow rates of all reagents (HCl, NaBH4, K3[Fe(CN)6]), atomization temperature and volume of sample loop. Under the optimal experimental conditions, the calibration was constructed and basic characteristics of the method were determined - sensitivity (0.0012 l∙μg-1 ), limit of detection (3.13 μg∙l-1 ). For interference measurement another hydride-forming elements (As, Se, Sb, Sn, Bi, Te), significant transition metals (Fe, Ni, Cu, Zn), alkali metal and alkaline earth metal (Na+ , Ca2+ ) and common anions (Cl- , SO4 2- , NO3 - ) including acetate anions were selected. Acetate anionswas incorporated to the study as a representative organic molecule. Hydride-forming elements, mainly selenium, were found as most serious interferents. E.g. selenium at low concentration increases absorption signal of lead. On the other hand, selenium at high...
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Spectrophotometric Determination of Chondroitine Sulphate by Sequential Injection Analysis
Hrubá, Lucie ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
This thesis deals with the optimization determination of chondroitin sulfate sequential injection analysis with spectrophotometric detection. The reaction proceeds in the presence of phenothiazine cationic dyes (Azure A, Azure B and methylene blue) and measuring the decrease absorbance dyes in their absorption maximum after the addition of chondroitin sulfate. Have found the optimum conditions for this determination: dye concentration 5 10-5 mole dm-3 , the dosing volume 100 µl CS + 50 µl dye + 100 µl CS, reaction time 0 s, flow rate 40 µl s-1 . For the determination of the CS in a static arrangement was found the lowest limit of detection and quantification using metylene blue (LOD = 0,23 mg l-1 a LOQ = 0,76 mg l- 1 ). The best repeatibility was achieved also using methylene blue 2,4 %. On the other side the best sensitivity was achieved using azure A. For the determination of the CS in SIA arrangement was found the lowest limit of detection and quantification using azure (LOD = 0,34 mg l-1 a LOQ =1,01 mg l-1 ). The best repeatibility was achieved also using azure A 1,9 %. And the best sensitivity was achieved using azure B. Based on these findings was chondroitin sulphate determined in food supplements, the more suitable method were the calibration curve .The determination was also carried out...
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Identification of polyphenolic compounds in plant extracts
Rýdlová, Iveta ; Rychlovský, Petr (advisor) ; Hraníček, Jakub (referee)
Thesis "Identification of selected polyphenols in extracts of medicinal plants" is divided into two parts. The first part is devoted to describing a general division polyphenolic compounds, their antioxidant activity and lists of the methods which are used for the analysis of these substances. The second part deals with the identification of these selected compounds using the RP - HPLC method with UV detection-DAD, and then with the tandem mass spectrometer with a triple quadrupole. The method was optimized, in this method was used gradient elution with 10-90% acetonitrile, 0,1% formic acid and deionized water. Analysis time was 38 minutes. Elution agents ran from polar to less polar substances. First of all eluted substances which contained the hydroxyl group directly on the benzene ring as e.g. phenolic acids, further eluted aglycones with bound sugar, which provides a higher polarity of the substance (flavanones glycosides), further followed the flavonols without attached saccharide units, at the latest the flavones eluted. This optimized method has proved to be reliable with good repeatability and accuracy for separation of polyphenols. Using the UV spectrometry the stability was measured. Due to the stability the substances proved to be stable compounds where their UV spectra don't change with...
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Determination of acetylsalicylic acid by sequential injection analysis with spectrophotometric detection
Vrtalová, Martina ; Hraníček, Jakub (advisor) ; Červený, Václav (referee)
This diploma thesis is focused on the determination of acetylsalicylic acid using two methods of flow analysis; Flow Injection Analysis (FIA) and Sequential Injection Analysis (SIA) with spectrophotometric detection. The principle of determination is based on the acetylsalicylic acid decomposition to give salicylic ion. This ion reacts subsequently with Fe3+ ion in acidic solution leading to colored chelating complex Fe(SAL)+ . The increase of absorbance of this complex in its absorption maximum was used for analytical determination. Sodium salicylate (sodium salt of acetylsalicylic acid) was used as a standard substance. In the first part of this work, experimental arrangement for flow injection analysis was setup. Continuously the optimization of experimental conditions of acetylsalicylic acid determination was performed to obtain the higher sensitivity. Under the optimal conditions the basic characteristics of determination was measured. In the second part of this work, the commercial experimental instrument FIA Lab 3500 was used for determination. Optimization of experimental conditions and basic characteristic of determination by sequential injection analysis was performed as well. Developed methods for determination of acetylsalicylic acid with selected technique were verified by analyzing...
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Application of non-membrane electrolytic cell for electrochemical volatile species generation of transition metals
Kobrlová, Andrea ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
This diploma thesis is focused on the study of electrochemical generation volatile species of gold and silver. Two non-membrane electrolytic cells were constructed for electrochemical generation volatile species. These cells differ in the volume of electrode chamber. An atomic absorption spectrometry with quartz tube atomizer was used in most experiments. The equipment was performed in flow continuous mode. Experiments confirmed, that it is possible to use an atomic absorption spectrometry with quartz tube atomizer for generate volatile species of gold and silver by using two non-membrane electrolytic cells. The main part of this thesis was to find optimal conditions for the electrochemical generation of volatile species of gold and silver. These optimized parameters were: the cathode material, the type of electrolyte, the flow rate of the carrier gas, the generation current and the electrolyte flow rate. The calibration curves for both analytes were measured for both non-membrane electrolytic cells and the basic characteristics of the measurement were observed. Detection limit for electrochemical generation of gold was 1,61mg dm 3 and repeatability 3,93 %, detection limit for electrochemical generation of silver was 0,20 mg dm 3 and repeatability 7,33 %. Thanks to the experiments with a...
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