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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 Lead using Sequential Injection Analysis with Spectrophotometric Detection
Mušutová, Martina ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
The main objective of the thesis was the determination of lead concentration in model aqueous solutions of 4-(2-Pyridylazo)-resorcinol complexating reaction with lead cation in 2-Amino-2-hydroxymethyl-propane-1,3-diol hydrochloride buffer (TRIS buffer). The UV/VIS molecular spectrometry in static arrangement was chosen with subsequent application of sequential injection analysis in flow arrangement. Calibration curve was measured and both methods were assessed. Detection threshold was 0,026 mg dm-3 in case of static arrangement and 0,70 mg dm-3 in case of flow arrangement. The interference analysis was performed, with metallic ions (Cu2+ , Zn2+ , Sn4+ ) being the most significant interferents, which also create a chromatic complex with 4-(2-Pyridylazo)-resorcinol. The interference effects were weak and almost not present for barium and potassium. Thesis concludes with determination of lead concentration in model specimen using flow arrangement. The determination by calibration curve was insufficient due to interfering ions and thus it had to be determined by standard addition method. Keywords Lead, 4-(2-pyridylazo)-resorcinol, TRIS buffer, flow sequential injection analysis, UV/VIS molecular spectrometry, interference effects
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Determination of Heparin by Sequential Injectin Analysis with Spectrophotometric Detection
Lišková, Růžena ; Hraníček, Jakub (advisor) ; Nesměrák, Karel (referee)
In this work the determination of heparin using Sequential Injection Analysis (SIA) technique with spectrophotometric detection was studied. The principle of this method was measuring the decrease of absorbance of phenothiazine dyes in its maximum wavelength caused by its interaction with heparin. The decrease is proportional to concentration of heparin in sample. The aim of this work was to find optimum conditions for determination of heparin by the SIA with spectrophotometric detection and to try to apply this measurement to real sample under these conditions. Three phenothiazine dyes were used: Methylene Blue, Azure A and Azure B and for each of them an optimum concentration was found. Their values were for methylene blue 4.0 ∙ 10-5 mol/dm3 and 5.0 ∙ 10-5 mol/dm3 for Azure A and Azure B. 150 µl was chosen as an optimum amount of heparin and reagent aspirated. Optimum reaction time was 0 s and flow rate during measurement 1.5 ml/min. Working concentration range was found between 0.23 and 15 mg/dm3 for methylene blue, 1.2 and 13 mg/dm3 for Azure A and 0.67 and 12 mg/dm3 for Azure B. Limit of detection varied between 0.09 - 0.35 mg/dm3 and limit of quantification between 0.30 and 1.2 mg/dm3 for different dyes. Relative standard deviation was determined as a measure of repeatability. Its values were...
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Determination of Procaine by Flow Injection and Sequential Injection Analysis with Spectrophotometric Determination
Tomanová, Marie ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
This diploma thesis is focused to the determination of procaine using flow injection and sequential injection analysis coupled with spectrophotometric detection. This determination is based on the reaction of procaine with a colouring agent, 1,2-naphthoquinone-4-sulfonic acid. An orange coloured product is formed, which is determined spectrophotometrically at the wavelength 484 nm. The high of the absorption signal of the product is directly proportional to the concentration of procaine. The aim of this work was to optimize the parameters of both methods of flow analysis so that the limit concentration of procaine can be as low as possible and at the same time, high sensibility is achieved. The next step was to apply these methods on the determination of procaine in real samples. It was found that in flow injection analysis, the absorbance of procaine hydrochloride obeys Beer's law for concentrations from 2.5 to 120 µg/ml. The linear regression equation of calibration graph was y = 0.0059x - 0.0051, with a linear regression correlation coefficient 0.9993. Limit of detection was 0.72 µg/ml. Effects of standing time (stopped-flow), flow rate, concentration of colouring agent, pH and the volume of the sample loop have been examined and optimized. It was also found that in sequential injection...
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Determination of Lead by Hydride Generation Atomic Absorption Spectrometry
Vošmiková, Anna ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
EN This diploma thesis presents the results of determination of lead amount in aqueous samples using chemical a electrochemical hydride generation methods. Both chemical and electrochemical generation methods are widely used for elemental analysis of the hydride forming elements in trace and ultra-trace levels. First of all the electrochemical generation method was used with HCl (1,0 mol dm-3 ) as anolyte. Determined analyte with the relevant concentration was added into the HCl solution (equal concentration). During the optimization experiments the electrochemical generation method was performed in different setups and constructions (eg. membrane, and non-membrane cells, different electrode materials). Also different acids (HNO3, H2SO4) of different concentrations were tested. Unfortunately achieved results were not satisfied and reproducible. Therefore, chemical generation method was used to provide relevant results. Determination of lead was performed in both and continuous flow and flow injection mode. A crucial step for chemical hydride generation insisted in usage of hexacyanoferrate (III) (17 % m/v solution for FIA and 2 % m/v solution for continuous flow) in solution of HCl on the relevant concentration. It was found that, K3[Fe(CN)6] significantly increases the efficiency of the chemical...
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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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Determination of barbituric acid by SIA-technique with spectrophotometric detection
Horáková, Jana ; Hraníček, Jakub (advisor) ; Jelínek, Ivan (referee)
This thesis is focused on the determination of barbituric acid using two methods of flow analysis: flow injection analysis and sequential injection analysis, with spectrophotometric detection. Two reactions were selected for the determination of barbituric acid and different experimental conditions were optimized conditions for its determination. In the case of flow injection analysis, the concentration and flow rates of many reagents, the sample volume and the volume of the reaction coil were optimized. In the case of sequential injection analysis the same parameters except the optimum volume of the reaction coil were optimized. The optimal volume of the reaction coil was replaced by the optimum retention time in the mixing coil. Determination of barbituric acid by reaction with a nitroaniline mixture achieved a calibration range from 2,0.10-6 to 1,2.10-4 mol dm-3 and from 3,9.10-6 to 6,2.10-5 mol dm-3 using using FIA and SIA method, respectively, under the optimal conditions. Determination of barbituric acid by inhibition effect on the reaction between hydrochloric acid and bromate ions served a calibration range from 5.10-6 to 3.10-5 mol dm-3 using FIA method and 2.10-5 to 1.10-4 mol dm-3 using methods SIA under optimal conditions. Powered by TCPDF (www.tcpdf.org)
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Electrochemical generation of tellurium and bismuth hydrides for AAS
Resslerová, Tina ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
Tellurium and bismuth are non-biogenous elements, which can be accumulated in human body. The aim of this work is focused on the determination of these elements by the electrochemical hydride generation with non-membrane electrolytic cell with quartz tube - atomic absorption spectrometry. The first step of the work was to optimize parameters for the continuous setup measurements and to obtain its figures of merit. After this, the arrangement with most suitable conditions for determination of these elements was converted to the flow injection setup (FIA) and all experimental parameters were again optimized and its figures of merit were obtained. The conditions of hydride generation were studied for platinum, lead and silver cathodes with hydrochloric and sulphuric acids and their sodium salts as electrolytes. The optimizations of the FIA setup were performed on platinum cathode in hydrochloric acid for bismuth and on lead cathode in sulphuric acid for tellurium. The limit of detection achieved for the generation of tellurium hydride was 1.1 ppm with a linear range up to 20 ppm; for the bismuth hydride the limit of detection was 9.5 ppm and limit of linearity 50 ppm. Keywords Bismuth, tellurium, electrochemical hydride generation, atomic absorption spectroscopy, flow injection analysis
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Chemiluminescence Determination of Cobalt and its Applications
Hrabalová, Veronika ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
Tato bakalářská práce se zabývá optimalizací metody stanovení kobaltu (resp. kobaltnatých iontů) pomocí průtokové metody analýzy, takzvané sekvenční injekční analýzy (SIA). Jako detekční technika je použita chemiluminiscence, která je následně detekována při vhodné vlnové délce 443,68 nm citlivým spektrofotometrem. Pro analytické účely se zde využívá katalytické schopnosti kobaltnatých iontů při chemiluminiscenční reakci luminolu s peroxidem vodíku. Intenzita detekovaného chemiluminiscenčního záření je přímo úměrná koncentraci kobaltnatých iontů. V souvislosti se stanovením kobaltu bylo nutné nejprve v SIA uspořádání optimalizovat některé významné parametry. Optimální koncentrace peroxidu vodíku byla 0,5 % a průtoková rychlost 4,0 ml.min-1 . Dále byly optimalizovány průtokové rychlosti a reakční objemy luminolu a vzorku. Za optimálních podmínek byly zjištěny základní charakteristiky stanovení kobaltu. Limit detekce byl 0,29 mg.l-1 , citlivost stanovení byla 481 l.mg-1 . Dále byla studována katalytická schopnost dalších 7 prvků, resp. jejich iontů (Cu2+ , Cr3+ , Fe3+ , Zn2+ , Mn4+ , Ag+ a Ni2+ ). Tato studie byla provedena z hlediska možných interferencí při stanovení kobaltu. Z výše uvedených iontů, pouze ionty Cu2+ vykazovaly katalytický účinek, který byl ovšem nevýznamný oproti iontům Co2+ . Při...
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Application of Atomic Absorption Spectrometry for Determination of Selected Elements from Potential Ecological Burden Area
Juránková, Lada ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
This work is focused on the determination of selected (chemical) elements (Fe, Mn, Zn, Cr, Na, K, Mg a Ca) in a potential ecological burden area using flame atomic absorption spectrometry as a detection technique. A potential ecological burden is represented by tires which are used as a construction material or as an environment surrounding for growing decorative and consumable plants. Analytes were determined in plant origin samples. Firstly, the samples were dried in a laboratory electric dryer. The weighted amount of a dried sample (approximately 0.2 g) was digested inside a microwave decomposition device with an addition of nitric acid and hydrogen peroxide. An optimization of experimental parameters was done for each of the elements before sample measuring. A burner height was optimized and 8 mm height was chosen as a optimum for most elements. Under the optimum condition basic characteristics were measured for each element separately. These characteristics included limits of detection that were: 0.05; 0.01; 0.08; 0.21; 0.02; 0.01; 0.01; 0.01 mg L-1 for the following elements: Fe, Mn, Zn, Cr, K, Ca, Mg and Na, respectively. The limits of quantification, sensitivity and repeatability were determined for each element as well. A significant attention was paid to the content of zinc in the studied...
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