National Repository of Grey Literature 146 records found  1 - 10nextend  jump to record: Search took 0.00 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...
HPLC in nutraceuticals analysis of chlorogenic acids
Majorová, Michaela ; Šatínský, Dalibor (advisor) ; Matysová, Ludmila (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Michaela Majorová Supervisor: Doc. RNDr. Dalibor Šatínský, Ph.D. Title of the diploma thesis: HPLC in nutraceuticals analysis of chlorogenic acids A new UHPLC method was developed and validated for determination of chlorogenic acids and their di-substituted derivates in nutraceuticals and the developed method was used for determination of chlorogenic acids in nutraceuticals Kilostop (Astina Pharm, a.s.), Zelená káva Extra (Medicura natural), Maxivitalis Zelená káva (Simply You Pharmaceuticals), Vieste Zelená káva Premium (Volt Retail), Zelená káva bylinný extrakt (Topvet), Zelená káva (VITO LIFE) a Kyselina chlorogenová (VITO LIFE). The analysis was performed on the Ascentis Express® RP-Amide (100 x 2.1 mm; 2.7 µm) column using gradient elution program with mobile phase consisted of mixture of acetonitrile and 5% aqueous solution of formic acid at flow rate of 0.9 ml/min, the PDA detector wavelenght was set at 325 nm and the column temperature was 30řC. Keywords: UHPLC, chlorogenic acid, green coffee extract, RP-Amide column, nutraceuticals
Application of HPLC technique in analysis of food supplements based on plant extracts
Fibigr, Jakub ; Šatínský, Dalibor (advisor) ; Cahlíková, Lucie (referee) ; Horna, Aleš (referee)
ABSTRACT Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Mgr. Jakub Fibigr Supervisor: doc. RNDr. Dalibor Šatínský, Ph.D. Title of the Dissertation Thesis: Application of HPLC technique in analysis of food supplements based on plant extracts The disseration thesis deals with complex issues of food supplements based on plant extracts in terms of the content of bioactive substances, purity assessment, and legislative efficacy and safety requirements. The quality of food supplements available on the market in the Czech Republic was tested in six studies. Two HPLC and four UHPLC methods have been developed and validated to determine the content of bioactive substances in food supplements containing plant extracts and other excipients. In each work, such analytical conditions were found allowing a rapid and accurate determination of the content of the given bioactive substances in food supplements, particulary in the problematic separations of some isomeric substances. Additionally, sample preparation methods for each group of food supplement samples have been developed and optimized to avoid the matrix interferences during the separation and detection of analyzed bioactive substances. A conventional approach to the analytical determination of 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...
Evaluation of separation potential of stationary phases based on porous graphitic carbon
Guláš, Ondrej ; Nováková, Lucie (advisor) ; Šatínský, Dalibor (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Ondrej Guláš Supervisor: Assoc. Prof. PharmDr. Lucie Nováková, Ph.D. Title of Diploma Thesis: Evaluation of separation potential of stationary phases based on porous graphitic carbon. Stationary phases based on porous graphitic carbon (PGC) exhibit many interesting features. For example high mechanical resistance, stability across the entire pH range and excellent high temperature resistance. Moreover, they are significant due to their unique mechanism of retention. Despite all of these positive features and long existence on the market, their broader use in pharmaceutical analysis is still lacking. In our paper we have analyzed 11 groups of drugs, including active pharmaceutical ingredient and its potential impurities. Overall, 67 substances have been analyzed. Each separation on PGC has been optimized in order to achieve the best results. Changes in conditions of separation included testing of several mobile phases, gradient and isocratic elution and testing the effect of higher temperature. The use of gradient elution, with mobile phase consisting of acetonitrile and isopropanol in proportion 1:1 as organic modifier and 0,1% trifluoracetic acid as aqueous part has appeared as the most...
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...
The testing of nanofiber polymers for stir bar sorptive extraction
Zatrochová, Slavomíra ; Šatínský, Dalibor (advisor) ; Chocholouš, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Slavomíra Zatrochová Supervisor: doc. RNDr. Dalibor Šatínský, Ph.D. Title of diploma thesis: Testing of nanofibrous polymers for extraction on a magnetic stirrer This thesis focuses on nanofibers polymers and their potential use for the sorption extraction on a magnetic stirrer (SBSE - stir bar sorptive extraction). The main aim of the work was to test selected types of polymer fibers and to prove their suitability as material for extraction on the magnetic stirrer. The presented work included the preparation of solutions to which we placed magnetic stirrers coated by nanofibers where the sorption extraction was carried out with selected substances. Afterwards chromatographic analysis and separation, the pre-concentrated substances on polymeric fibers was evaluated. After several measurements we found out that the extreme lipophilic analytes such as Sudan dyes were irreversibly adsorbed on polymeric fibers. Polystyrene fiber (PS) was not stable in used organic solvents and therefore was prepared again before every extraction. The highest theoretical enrichment factor (100) has not been achieved at any used nanofiber. In conclusion, we can say which selected kinds of polymeric fibers are suitable...
Extraction of zinc from water solutions using solid phase extraction in sequential injection analysis
Klinerová, Jana ; Chocholouš, Petr (advisor) ; Šatínský, Dalibor (referee)
v angličtině Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical chemistry Candidate: Bc. Jana Klinerová Supervisor: PharmDr. Petr Chocholouš, Ph.D. Title of diploma thesis: Extraction of zinc from water solutions using solid phase extraction in sequential injection analysis This work is devoted to the extraction of zinc from aqueous samples by solid phase extraction in sequential injection analysis. Zinc extraction was tested with solutions of three concentrations (100 nmol/l, 200 nmol/l, 500 nmol/l) using four different chelating sorbents (Iontosorb OXIN, Iontosorb SALICYL, Iontosorb IDA a Toyopearl) at seven different conditions (pH of 3, 4, 5, 6, 7, 8 and 9) of the wash buffer and at pH 2 of the elution solution. During the detection was monitored absorbance of zinc complex with the reagent 4-(pyridyl-2-azo) resorcinol at wavelengths of 490, 510, 560 and 600 nm. In comparison of the four sorbents under different conditions of measurement was determined as the best sorbent Iontosorb OXIN and suitable conditions for the extraction - pH of the wash buffer and of the sample 6 and higher.

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