National Repository of Grey Literature 149 records found  beginprevious31 - 40nextend  jump to record: Search took 0.00 seconds. 
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...
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
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)
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...
Study of properties of UV-photochemical generation of volatile compounds od antimony
Adámková, Dominika ; Červený, Václav (advisor) ; Hraníček, Jakub (referee)
The master thesis deals with comparison of atomic fluorescence spektrometry and high resolution continuum source atomic absorption spektrometry for three methods generation of volatile compounds Antimony. In both methods of atomic antimony detection, it compares the most common chemical generation of volatile compounds (hydrides) with two alternative methods - electrochemical and UV - photochemical. The values of performance parameters for the determination of Sb(III) and Sb(V) were determined for all the above combinations. In the case of chemical generation, a surprisingly almost four times higher limit of detection of Sb(III) was found in connection with AFS detection than AAS detection. The final part was devoted to UV - photochemical vapor generation, with AAS detection for Sb(III) reaching limit of detection 4,96 ppb, for Sb(V) 8,63 ppb. Although UV - photochemical generation of volatile antimony compounds did not reach such performance parameters as chemical or electrochemical generation, it was observed that the sensitivity of antimony determination increased greatly when introducing oxygen into the apparatus. The interference study also found a significant positive effect of Fe(II) on the generation efficiency, and this modification partially persisted without further introduction of these...
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...
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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