National Repository of Grey Literature 151 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Development of HPLC method for determination of selected phenolic acids and flavonoids in Tokaj wines
Moravcová, Pavlína ; Šatínský, Dalibor (advisor) ; Lhotská, Ivona (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical chemistry Candidate: Bc. Pavlína Moravcová Supervisor: Doc. RNDr. Dalibor Šatínský, Ph.D. Title of the diploma thesis: Development of HPLC method for determination of selected phenolic acids and flavonoids in Tokaj wines The aim of this diploma thesis was to develop and optimize HPLC method for simultaneous determination of 15 phenolic compounds, protocatechic acid, fertaric, coffee, p-hydroxybenzoic, syringic, gallic, p-coumaric, ferulic, chlorogenic, caftaric, 2-hydroxy-4-methoxybenzoic , polydatin, resveratrol, catechin hydrate and epicatechin in Tokaj wines. The quantity and content of selected phenolic compounds was analyzed in 25 samples of Tokaj wines, which come from vineyards from the Slovak part of Tokaj wine region. The work was also focused on the description of the specific characteristics of this unique area, the unique method of Tokaj wine production, its chemical composition, and namely the spectrum of phenolic substances. Analysis of selected phenolic compounds was performed using an Ascentis® Express F5 column (150 x 4.6 mm; 5 µm) using a mobile phase consisting of 0.1% phosphoric acid and acetonitrile in gradient elution. The substances were analyzed at 30 řC and flow rate of 1 ml/min and detected...
Development of on-line SPE HPLC method for determination of ochratoxin A in Tokaj wines
Uhrová, Adéla ; Šatínský, Dalibor (advisor) ; Chocholouš, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Adéla Uhrová Supervisor, consultant: Doc. RNDr. Dalibor Šatinský, Ph.D. Title of Diploma Thesis: Development of on-line SPE HPLC method for determination of ochratoxin A in Tokaj wines This diploma thesis deals with the optimization and validation of chromatographic method for determination of ochratoxin A in Tokaj wine with subsequent application on real samples. A high- performance liquid chromatography method with fluorescence detection using on-line extraction by column switching has been developed. 50µl of sample was injected directly in the extraction column, where at 1st minute the analyte was extracted on the Ascentis® Express RP-Amide precolumn in the presence of a mobile phase of 40% MeOH in 0.5% aqueous acetic acid. After the extraction, the valve was switched and the extracted substances were separated on a YMC Triart C18 ExRS analytical column. The separation was carried out under gradient elution with an initial acetonitrile ratio of 45% in the mobile phase, which reached a concentration of 80% in the 5th minute. Fluorimeter detection was optimized for excitation and emission wavelengths ʎEx 335 nm and ʎEm 463 nm. In the last part of the work, ochratoxin A was analyzed in real...
Evaluation of selected substances in fruit by HPLC-DAD-CAD method
Košková, Stanislava ; Sklenářová, Hana (advisor) ; Šatínský, Dalibor (referee)
Charles University Faculty of Pharmacy in Hradci Králové Deparment of Analytical Chemistry Candidate: Bc. Stanislava Košková Supervisor: Doc. PharmDr. Hana Sklenářová, Ph.D. Consultant: Ing. Radek Vávra, Ph.D. (VŠÚO Holovousy) Title of diploma thesis: Evaluation of selected substances in fruit by HPLC-DAD-CAD method Thisdiploma thesis was focused on determination of seven phenolic compounds, namely gallic acid, chlorogenic acid, epicatechin, rutin, phloridzin, quercetin, phloretin in twenty apple cultivars, that have been delivered by the Research and Breeding Institute of Pomology Holovousy s.r.o. For this purpose HPLC separation in reverse mode was used, using the column Omega Polar C 18 (150 mm x 4.6 mm; 5 µm). As the mobile phase the mixture of an ultrapure water acidified with the acetic acid to pH 2.8 and acetonitrile was used. A linear gradient was chosen with a gradual increase of the organic component from the initial 10 % to 50 % during 10 min of separation.This was followed with column equilibration - up to 12.50 min to 10 % organic component. The overall separation time was 12.50 min at a flow rate of 1 ml/min. Column temperature was set to 30 řC. Detection was performed using DAD (254, 280, 320 nm) and CAD detector (nebulizer temperature 25 řC). Part of this thesis is system...
Development of HPLC method for determination of coumarins in Tokaj wines
Sudová, Tereza ; Šatínský, Dalibor (advisor) ; Sklenářová, Hana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Tereza Sudová Supervisor: Doc. RNDr. Dalibor Šatínský, Ph.D. Title of the diploma thesis: Development of HPLC method for determination of coumarins in Tokaj wines A high performance chromatography method was used for simultaneous determination of coumarins: umbelliferone (7-hydroxycoumarin), coumarin and 7-methoxycoumarin (herniarin) in 60 samples of Tokaj wines and 12 samples of wines and spirits. Before the analysis, HPLC parameters were optimized: detector wavelength, analytical column, mobile phase and gradient elution. The suitability of the HPLC method for the determination of coumarins was confirmed. Then the method was validated by a validation process. The analysis was performed under gradient elution conditions with mobile phase methanol (organic phase) and 0.1% phosphoric acid (aqueous phase) at a flow rate of 1 ml/min. Ascentis® Express F5 - 150  4.6 mm reversed phase column at a temperature of 30 řC was used. The particle size of the stationary phase was 5 µm. Coumarins were detected by a DAD detector at wavelenghts 276 nm and 323 nm. Untreated samples were injected in a volume of 5 µl. The total analysis was 15.51 min.
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...

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