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Possibilities of electrochemical generation of volatile compound of silver
Linhart, Ondřej ; Hraníček, Jakub (advisor) ; Červený, Václav (referee)
The presented bachelor thesis is to focus on the possibilities of electrochemical generation of volatile form of silver coupled with atomic absorption spectrometry which was used as a detection technique. The main aim was to optimize working parameters. A thin-layer electrolytic cell and a tubular electrolytic cell have been tested for the electrochemical generation of volatile form of silver. The optimization of appropriate electrolyte, its concentration and its flow rate, electric current and flow rate of carrier gas have been developed. Under the optimal working conditions the sensitivity of 0.029 dm mg-1 for the determination of silver by electrochemical generation was achieved.
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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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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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SEQUENTIAL INJECTION ANALYSIS CAPABILITY IN AUTOMATION OF ANALYTICAL PROCESSES
Novosvětská, Lucie ; Sklenářová, Hana (advisor) ; Polášek, Miroslav (referee) ; Hraníček, Jakub (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate (married name/maiden name): Mgr. Lucie Novosvětská / Mgr. Lucie Zelená Supervisor: assoc. prof. PharmDr. Hana Sklenářová, Ph.D. Consultant: PharmDr. Petr Chocholouš, Ph.D. Title of dissertation thesis: Sequential injection analysis capability in automation of analytical processes This dissertation, composed as a commented collection of four scientific articles and one undergoing project, introduces four novel applications in the field of automated flow methods and one application in the field of chromatographic methods used in analytical part of a complex pharmacological study. It the field of pharmaceutical analysis, three works were successfully optimized, validated, and published in scientific journals. Those works include: a) Automation of permeation studies within a sequential injection analysis system connected to a liberation unit and carrying out experiments with living cells. b) Pharmacological study of an antiretroviral drug efavirenz including its determination by fast chromatographic method in three types of sample matrices - in a medium from permeation studies with cellular models, in a Krebs solution from rat placenta perfusions, and in placenta tissue lysates. c) Determination of...
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Determination of lead and zinc in great tits blood
Greguš, Viktor ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
EN Determination of heavy metals in urban living passerine birds organism has been considered as suitable method for monitoring pollution of human enviroment which these elements can cause. This study deals with determination of zinc and lead in dried great tits blood samples using inductively coupled plasma-mass spectrometry technique. Dried blood samples were weighed, solubilized in nitric acid and hydrogen peroxide and microwavelly digested. Calibration standards for determined elements were prepared and basic analytical characteristics of the measurement were determined. Matrix interference was examined by measuring the recovery of element determination presented as a ratio of the slope of standard addition to the certified reference material of whole blood sample and the slope of external calibration.
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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 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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Possibilities of electrochemical generation of volatile compound of gold
Průša, Libor ; Hraníček, Jakub (advisor) ; Musil, Stanislav (referee)
The possibilities of electrochemical generation of gold volatile compound have been studied in this work. All experiments have been employed in electrochemical continuous flow generation. The previous aim of this work was to investigate if it is possible to generate the volatile form of gold using electrochemical generation of volatile compounds. Lead, platinum and alloy of lead and tin were used as cathode materials. Consequently, optimizations of experimental conditions were carried out. The optimized experimental conditions were: carrier gas flow rate, flow rate of electrolytes, electric current used for electrochemical generation, influence of the different types of gas-liquid separator, atomizer temperature. The calibration and other characteristics were found. At the conclusion, effect of oxygen on the signal intensity was studied. Key words Electrochemical generation of volatile compound atomic absorption spectrometry quartz tube atomizer flow-through electrolytic cell volatile compound gold
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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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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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