National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
On-line SPE-HPLC method development for determination of zearalenone in beers
Gajdošová, Barbora ; Šatínský, Dalibor (advisor) ; Karlíček, Rolf (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Barbora Gajdošová Supervisor: Doc. RNDr. Dalibor Šatínský, Ph.D. Title of Diploma Thesis: On-line SPE-HPLC method development for determination of zearalenone in beers High performance liquid chromatography coupled with on-line solid phase extraction (SPE) using the column switching technique for sample preparation was utilized for the development of the method for the determination of mycotoxin zearalenone in beer. Two different SPE sorbents were tested. A volume of 50 µl of beer sample was injected directly into the chromatographic system. After injection, the sample extraction of zearalenone from the matrix was carried out on SPE precolumn Ascentis® Express C18 Guard Cartridge (5 x 4.6 mm, 5 µm), which is based on the reverse phase, or on SPE precolumn (10 x 4.6 mm) filled with Affinimip® SPE Zearalenone sorbent, a specific Moleculary Imprinted Polymer, designed for the selective extraction of zearalenone. 40% methanol - 2% water solution of acetic acid was selected as the washing solution for removing ballast matrix for the C18 extraction column and 10% acetonitrile - 2% water solution of acetic acid for the Affinimip column. These washing solutions were flowed through the...
Modern chromatographic techniques in food contamination analysis
Lhotská, Ivona ; Šatínský, Dalibor (advisor) ; Karlíček, Rolf (referee) ; Malíř, František (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate Mgr. Ivona Lhotská Supervisor doc. RNDr. Dalibor Šatínský, Ph.D. Title of Doctoral Thesis Modern chromatographic techniques in food contamination analysis A compilation of seven publications dealing with chromatographic methods for determination of food contamination (particularly mycotoxins and artificial food colorants) is presented in dissertation thesis. All methods were fully validated, complying with the requirements and applied for real samples analysis. The first part describes the methods for mycotoxins determination based on on-line solid phase extraction (SPE) utilizing column-switching system. Reversed phase columns packed with superficially porous particles were chosen for both extraction and separation step during optimization of on-line SPE-HPLC method for ochratoxin A and citrinin determination in beer. In following work, determination of patulin in juices and zearalenone in beer, more selective molecularly imprinted polymers (MIP) were used for on-line extraction. Due to challenging optimization of on-line MIP SPE, the methods were compared to off-line MIP extraction and on-line extraction using conventional C18 phase to confirm the selectivity. The employed commercial MIP...
Determination of mycotoxin citrin using on-line SPE HPLC on molecularly imprinted polymers
Kholová, Aneta ; Šatínský, Dalibor (advisor) ; Karlíček, Rolf (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Aneta Kholová Supervisor: Doc. RNDr. Dalibor Šatínský, Ph.D. Title of Diploma Thesis: Determination of mycotoxin citrinin using on-line SPE HPLC on molecularly imprinted polymers The aim of this work was to develop a fast method for mycotoxin citrinin (CIT) determination using high performance liquid chromatography (HPLC) and column switching technique in combination with on-line solid phase extraction (SPE) based on citrinin-selective molecularly imprinted polymer (MIP). The most suitable sorbent for selective extraction was chosen from six newly synthetized MIP after evaluation of their binding capacity and selectivity. Selectivity was tested by comparing molecularly imprinted and non-imprinted polymers and the ability of the MIP polymer to selectively separate citrinin from interferences of the test sample. The best MIP (functional monomer of metacrylamide with porogen acetonitrile) was filled into pre-column (20 × 3 mm) and connected to HPLC column-switching system. Three different matrices were injected to chromatographic system. 50 μl of the sample was injected onto MIP extraction column and washed out of interferences with methanol / 0.5% water solution of acetic acid in a ratio of...
On-line SPE-HPLC method development for determination of zearalenone in beers
Gajdošová, Barbora ; Šatínský, Dalibor (advisor) ; Karlíček, Rolf (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Barbora Gajdošová Supervisor: Doc. RNDr. Dalibor Šatínský, Ph.D. Title of Diploma Thesis: On-line SPE-HPLC method development for determination of zearalenone in beers High performance liquid chromatography coupled with on-line solid phase extraction (SPE) using the column switching technique for sample preparation was utilized for the development of the method for the determination of mycotoxin zearalenone in beer. Two different SPE sorbents were tested. A volume of 50 µl of beer sample was injected directly into the chromatographic system. After injection, the sample extraction of zearalenone from the matrix was carried out on SPE precolumn Ascentis® Express C18 Guard Cartridge (5 x 4.6 mm, 5 µm), which is based on the reverse phase, or on SPE precolumn (10 x 4.6 mm) filled with Affinimip® SPE Zearalenone sorbent, a specific Moleculary Imprinted Polymer, designed for the selective extraction of zearalenone. 40% methanol - 2% water solution of acetic acid was selected as the washing solution for removing ballast matrix for the C18 extraction column and 10% acetonitrile - 2% water solution of acetic acid for the Affinimip column. These washing solutions were flowed through the...
The Use of Modern Chromatographic Approaches and Sample Preparation in the Analysis of Biologically Active Substances
Brabcová, Ivana ; Šatínský, Dalibor (advisor) ; Karlíček, Rolf (referee) ; Tolarová, Jitka (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Mgr. Ivana Brabcová Supervisor: Doc. RNDr. Dalibor Šatínský, Ph.D. Title of thesis: The use of modern chromatographic approaches and sample preparation in the analysis of biologically active substances The presented thesis deals with the modern trends in liquid chromatography and in the analysis of biologically active substances. High performance liquid chromatography (HPLC) is an important analytical tool for separating and quantifying components of mixtures. New trends of HPLC technology tend to development of new stationary phases with better properties. Another trend in analytical chemistry is a miniaturization of the HPLC system and environmentally friendly chromatography. Sample preparation is an essential step in analysis, greatly influencing the reliability and accuracy of analysis. Nowadays, the development is focused on new modern techniques of sample preparation. The developments of these techniques lead up to miniaturization, automatization and preconcentration of target analytes. The theoretical part of the thesis deals with the introduction of modern trends in liquid chromatography and it is divided in several sections. First part describes current trends in fast liquid...
Using of Flow Analytical Method for Determination of Biological Active Compounds
Koblová, Petra ; Solich, Petr (advisor) ; Karlíček, Rolf (referee) ; Cabal, Jiří (referee)
Disertační práce Abstract 1 Abstract Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Mgr. Petra Koblová Supervisor: prof. RNDr. Petr Solich, CSc. Title of Doctoral Thesis: Using of flow analytical method for determination of biological active compounds The presented dissertation thesis is dealing with development of HPLC and SIC methods for determination of active substances and degradation products in pharmaceutical formulations. Developed methods were validated and meet all requirements for suitability, precision and reliability. In the first work, HPLC method for determination of active compound clotrimazole and its degradation products (2-chlorophenyl) diphenylmethanol and imidazole in Clotrimazol spray 1 % was developed. Ibuprofen was used as the internal standard. The aim of the next work was to compare separation efficiency particle based and monolithic columns with various lengths. HPLC method for determination of indomethacin and its two degradation products was used for comparison. Ketoprofen was used as an internal standard for data evaluation throughout the study. SIC method for determination of water-insoluble vitamins (retinol acetate, D2, or D3 and tocopherol acetate) was developed. The novel SIC method with the monolithic...
Analysis of selected natural compounds by modern separation methods
Citová, Ivana ; Solich, Petr (advisor) ; Ševčík, Juraj (referee) ; Karlíček, Rolf (referee)
7 Summary The presented dissertation thesis deals with an extensive topic of natural compounds analysis by the means of modern separation techniques described from different points of view. Firstly, theoretical information about studied natural compounds (mainly antioxidants) has been summarized including characterization of the mechanism of free radicals formation and development of oxidative stress in human organism. Furthermore, the function of antioxidants and key roles of antioxidant therapy have also been discussed. Within the analyzed antioxidants, biological and physicochemical properties of phenolic acids, vitamins A and E and polyunsaturated fatty acids are described. Concurrently, known and published analytical procedures applied on each group of compounds are summarized. Besides antioxidants, content substances of yellow gentian (dried roots of Gentiana lutea) have been analyzed. Information about gentian pharmacological action, its practical utilization in therapy and ways of analytical determination represents the last chapter of theoretical part dealing with the studied compounds. The second point of view comprises characterization of individual separation techniques used in the thesis. Basic principles of gas chromatography (GC), solid phase microextraction connected to GC (SPME-GC), Ultra...
The comparison of different types of stationary phases in HPLC analysis of medicament Diclofenac emulgel
Poláčková, Jitka ; Karlíček, Rolf (referee) ; Matysová, Ludmila (advisor)
The aim of this rigorous work is a comparison of different types of stationary phases for the analysis of the drug Diclofenac emulgel. It is necessary to take into account the many specialized materials from the pharmacopoeias, ICH guidelines and professional scientific journals in solution of the development of HPLC methodology, validation and choice of stationary phase analytical columns. Several types of stationary phases were tested, with the testing of conditions of the separation of active substances from the pharmaceutical formulation - diclofenac emulgel. The best results were placed on Discovery HS-F5 (15 cm x 4.6 mm, 5 m), time analysis was less than 4 minutes; Zorbax SB - CN (4.6 x 150 mm, 5 m) time of analysis was less than 5 min; Chromolith Performance RP - 18e (100 - 3 mm) time analysis was less than 3 minutes.
Application of modern technologies for treatment of biological samples for HPLC analysis.
Dědečková, Klára ; Karlíček, Rolf (referee) ; Solich, Petr (advisor)
This diploma thesis is dealing with a using of new technologies for the treatment of biological material in the HPLC analysis. The main aim of this thesis was miniaturization of solid phase extraction process of blood serum on classical SPE columns to SPE plates for determination of liposoluble vitamins A and E by high performance liquid chromatography. The new extraction method for vitamin A and E in blood serum using the modern format of SPE plate was developed and optimized. This new method mineralizes a blood serum volume, makes sample treatment easy and can speed up the analysis.

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