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Solid phase extraction and its miniaturization by method Lab-On-Valve
Krchňáková, Eva ; Chocholouš, Petr (advisor) ; Sklenářová, Hana (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical chemistry Candidate: Bc. Eva Krchňáková Supervisor: PharmDr. Petr Chocholouš, Ph.D. Title of diploma thesis: Solid phase extraction and its miniaturization by method Lab-On- Valve. This thesis deals with the ability to automate solid phase extraction (SPE), in connection with the bead injection (BI). The aim was to test the replacement of microparticles in the bead injection with sorbent from SPE cartridges, determinate the behavior of sorbent in this system and then determine whether it is possible to miniaturize all the steps of solid phase extraction that are necessary to implement the method. In the work was done manual solid phase extraction, where were tested seven sorbents: Lichrolut Merck RP-18, DSC-18 DSC-18Lt, DSC-8, PH-DSC, DSC-CN and Oasis HLB. The experiment resulted in the best possible conditions for carrying out solid phase extraction as follows: activation of the sorbent and elution of analyte 100% acetonitrile, solvation of the sorbent, the dissolution of vitamin D and ballast from the sorbent washed with dilute acetic acid of pH 3. Oasis HLB from Waters Company is the most suitable sorbent for the system, which is water-wettable and should not be dispersed by the system, which was...
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On-line solid phase extraction using sequential injection analysis
Hadysová, Zuzana ; Chocholouš, Petr (advisor) ; Sklenářová, Hana (referee)
Department: Department of Analytical chemistry Candidate: Bc. Zuzana Hadysová Supervisor: PharmDr. Petr Chocholouš, Ph.D. Title of the diploma thesis: On-line solid phase extraction using sequential injection analysis This diploma thesis is focused on the comparison of three sorbents (Iontosorb OXIN 50, Iontosorb Oxin 100 and TOYOpearl AF-chelate-650M) with the aim to find the most suitable one for analysis of Zn2+ using on-line solid phase extraction based on sequential injection analysis. Zinc sulphate solutions at concentrations of 25 nmol/l, 50 nmol/l, 100 nmol/l, 200 nmol/l, 500 nmol/l, 1000 nmol/l, 1500 nmol/l and 2000 nmol/l were used in this work. During the analysis was used the buffer at pH 6, the elution solution HCl at pH 1 and the reagent 4-(2-Pyridylazo)resorcinol (PAR). The effort was to extract Zn2+ at the lowest possible concentrations. Tested parameters were calibration range and repeatability. The best sorbent in comparison was Iontosorb OXIN 100.
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Evaluation of phenolic compounds content in fruits
Baďurová, Kristýna ; Sklenářová, Hana (advisor) ; Šatínský, Dalibor (referee)
Charles University Faculty of Pharmacy in Hradci Králové Department of Analytical Chemistry Candidate: Bc. Kristýna Bortlová Supervisor: Doc. PharmDr. Hana Sklenářová, Ph.D. Title of Diploma Thesis: Evaluation of phenolic compounds content in fruits This diploma thesis is focused on the analysis of selected phenolic compounds (gallic acid, chlorogenic acid, epicatechin, rutin, quercitrin, phloridzin and phloretin). The content of these phenolic substances was evaluated in ten selected varieties of apples using an optimized HPLC method. A general description of phenolic substances is included in the thesis. Further, the thesis contains a short review of scientific publications devoted to the content of phenolic substances in fruits and a short description of the HPLC method for determination of phenolic substances. HPLC analysis was performed on the guard column Ascentis Express C18 (5 x 4.6 mm x 5 μm), and separation columns Kinetex C18 (150 x 4.6 mm x 5 μm) with core- shell particles and Luna Omega Polar C18 column (150 x 4.6 mm x 5 μm) with fully porous particles. Detection was performed by a UV detector at wavelengths of 255, 280, 320 and 365 nm. The injected volume was 10 μl and a flow rate of 1 ml/min at column temperature of 30 řC was used. A gradient elution of the mobile phase was applied...
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Determination of ferric ions in the SIA system with chemiluminescence detection
Blahynková, Michaela ; Sklenářová, Hana (advisor) ; Chocholouš, Petr (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Michaela Blahynková Supervisor: Doc. PharmDr. Hana Sklenářová, Ph.D. Title of Diploma Thesis: Determination of ferric ions in the SIA system with chemiluminescence detection Catalytic influence of ferric ions on the oxidation of luminol using hydrogen peroxide in alkaline environment has been observed through chemiluminiscence detection. The sequence of sample and reagent aspiration, their volumes, mixing flow rate and flow rate through the detector have been optimized. The influence of mixing, various ferric compounds, and the presence of ferrous ions on the intensity of chemiluminiscence have also been tested. The resulting optimization was an aspiration sequence of 50 µl of 10-3 mol∙l-1 H2O2, 50 µl of 10-3 mol∙l-1 K3[Fe(CN)6], 50 µl of 10-3 mol∙l-1 luminol. Solution aspiration speed was 100 µl·s-1 , flow rate through detector was 70 µl·s-1 . Calibration dependence of chemiluminiscence intensity on ferric ion concentration at low concentrations (10-7 - 10-9 mol·l-1 ) was non-linear. Linear area of calibration for Fe3+ ions at standard conditions has not been found with correlation coefficient high enough, therefore polynomial calibration dependence of second degree with correlation...
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Automation of liberation tests for releasing biologically active substances from nanofibers
Schneidrová, Marie ; Sklenářová, Hana (advisor) ; Chocholouš, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of analytical chemistry Candidate: Marie Schneidrová Supervisor: doc. PharmDr. Hana Sklenářová, Ph.D. Title of the diploma thesis: Automation of liberation tests for releasing biologically active substance from nanofibers The main goal of this diploma thesis is an automation of TTC liberation from nanofibers, using non-separation flow method sequential injection analysis. UV-VIS spectrophotometer was used for the detection of signal. Measurements were carried out using 1-3 connected Franz cells in parallel, palced in the water bath. Buffer solutions with pH 7.4 and 4.5 were used as liberation media. The liberation of TTC was realized from two different nanofiber carriers - types "A" and "AK", Difference was in their preparation process. Because of this, each of them revealed various characteristics mainly related to the amount of bound TTC and the way of its binding to the nanofiber carrier. Production of these nanofibers was realized by Technical University Liberec using the technology NanoSpiderTM . Measurements were performed under various predetermined conditions, representing the state of the human skin - two different pH (7.4; 4.5) and temperature (32řC; 37řC) values. Four different types of membrane filters were also used,...
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Testing antioxidant activity using luminol chemiluminescence system
Chládková, Gabriela ; Sklenářová, Hana (advisor) ; Kujovská Krčmová, Lenka (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Gabriela Chládková Supervisor: Doc. PharmDr. Hana Sklenářová, Ph.D. Consultant: Doc. RNDr. Miroslav Polášek, Csc. Title of Diploma Thesis: Testing antioxidant activity using luminol chemiluminescence systém The aim of the thesis was to compare various conditions for the testing of the antioxidant activity by means of the luminol chemiluminescent system in the flow system, and evaluation of dependence of the antioxidant efficacy on concentration. The antioxidant efficacy was described as dependency of the decrease of a chemiluminescence signal on the used concentration of an antioxidant. Efficacy of three substances - resveratrol, p-coumaric acid and trolox was observed. Trolox was used as a standard substance in evaluation of the antioxidant activity. The chemiluminescence system was based on a chemiluminescent reagent. In this particular case we used luminol in a sodium hydroxide solution or in a sodium carbonate solution adjusted to pH 10 or without pH adjustment. Luminol demonstrated chemiluminescence emission after oxidation with hydrogen peroxide in the presence of catalysts. As the catalyst, potassium hexacyanoferrate(III) or potassium hexacyanoferrate(II) were used. The working...
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HPLC separation of p-aminophenol, paracetamol, caffeine and propyphenazone on polar stacionary phase.
Maroušková, Alena ; Šatínský, Dalibor (advisor) ; Sklenářová, Hana (referee)
This thesis deals with finding optimal chromatographic conditions for a separation of p- aminophenol, paracetamol, caffeine and propyphenazon by HPLC. These analytes have different polarity and acidobazic properties. The application of traditional octadecylsilane stationary phases for their simultaneous determination is problematical. The PEG column have proved to be suitable for an efficient separation of the analytes with different polarities, i.e. with different chromatographic behavior. The resulting method brings shortening of analysis time, which is important for analysis of big series . Within the optimization of chromatographic conditions: a wide range of mobile phases has been tested (various organic solvents, various ratio of organic components to water phase components) a various level of acidity of the mobile phase has been tested ranging from 4 to 7 pH units various buffers have been tested behavior of the analytes has been tested under an enhanced temperature two PEG columns with different lengths have been tested Optimal chromatographic conditions for a separation of the analytes mentioned above, as well as the fulfillment of requirements for simplicity, analysis time and high degree of reliability have been found. The final chromatographic conditions: Stationary phase:...
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Determination of Co (II) ions in the SIA system with chemiluminescence detection
Köszegy, Erik ; Sklenářová, Hana (advisor) ; Chocholouš, Petr (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of analytical chemistry Candidate: Erik Köszegy Supervisor: Doc. PharmDr. Hana Sklenářová, Ph.D. Title of Diploma Thesis: Determination of Co (II) ions in the SIA system with chemiluminescence detection The thesis deals with the determination of cobalt(II) ions using the sequential injection analysis technique with chemiluminescence detection. The chemiluminescent reaction based on luminol oxidation by hydrogen peroxide a flow-through system in the presence of cobalt(II) ions in an alkaline solution serves as the basis for the determination. Trace amounts of cobalt(II) ions act as a catalyst in the chemical reaction. Apparatus used, consists of a standard SIA system with a flow-through cell formed by a transparent Teflon coil tube, which is suitable for conducting chemiluminescent measurements. Emitted radiation was detected using a sensitive photomultiplier. The reaction was carried out in the system following an optimization of reaction conditions. The sensitivity and repeatability of the chemiluminescence reaction was subsequently examined. To determine the calibration dependence a solution of hydrogen peroxide and luminol in 0.1 M NaOH and a solution of the sample containing cobalt(II) ions in graded concentrations...
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