National Repository of Grey Literature 165 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
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...
Comparison of methods for determination of amphetamine derivates in meconium
Vrbová, Romana ; Matysová, Ludmila (advisor) ; Šatínský, Dalibor (referee)
Department: Department of Analytical Chemistry Candidate: Romana Vrbová Supervisor: doc. PharmDr. Ludmila Matysová, Ph.D. Title of the diploma thesis: Comparison of methods for determination of amphetamine derivates in meconium The aim of the bachelor thesis was to optimize a new method for the determination of amphetamine derivatives in meconium, which will be faster and simpler than the existing routine method in the toxicological laboratory of Masaryk's Hospital in Ústí nad Labem. The theoretical part of the bachelor thesis describes the main representatives of amphetamine derivatives, their effects and metabolism. Their determination in meconium is important for the diagnosis of Neonatal abstinence syndrome, which occurs in newborns of mothers using addictive substances during pregnancy. Meconium, the first stool of a newborn, is a suitable material demonstrating exposure to drugs and medication during the second and third trimesters of pregnancy. Amphetamine derivatives were determined in meconium by gas chromatography with mass detection, the principles and instrumentalization of which are another part of the bachelor's thesis. The experimental part describes the optimization of a new, more advantageous method using pentafluorobenzoyl chloride as a derivatizing agent and its comparison with...
Development of CE-C4D method for the analysis of saccharides in honey
Šebestová, Gabriela ; Jáč, Pavel (advisor) ; Šatínský, Dalibor (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Gabriela Šebestová Supervisor: PharmDr. Pavel Jáč, Ph.D. Title of the diploma thesis: Development of CE-C4D method for the analysis of saccharides in honey Honey is a commonly used natural mixture which quality must be monitored due to possible mishandling or adulteration. This diploma thesis is focused on the development of a capillary electrophoresis method with capacitively coupled contactless conductivity detection (CE-C4D) for the determination of carbohydrates in honey samples. Design of Experiments (DoE) was used to optimize the separation conditions. This approach allows to find suitable separation conditions by means of multivariate optimization. During the optimization, the impact of the following factors was investigated: the composition of the background electrolyte, the separation voltage and temperature during separation and the inner diameter of the separation capillary. Two methods were optimized: one with normal electroosmotic flow (EOF) and the other using reversed EOF after CTAB addition. The method in the normal EOF mode was used for validation and analysis of honey samples. A fused silica capillary with an inner diameter of 20 m, a total length of 48.7 cm and an effective...
HPLC separation of phenolic substances in plant material
Majerčíková, Jana ; Sklenářová, Hana (advisor) ; Šatínský, Dalibor (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Jana Majerčíková Supervisor: doc. PharmDr. Hana Sklenářová, Ph.D. Title of the diploma thesis: HPLC separation of phenolic substances in plant material This diploma thesis is focused on development and optimization HPLC-DAD method for determination of 17 phenolic compounds (gallic acid, protocatechuic acid, 4-aminobenzoic acid, chlorogenic acid, catechin, caffeic acid, epicatechin, vanillin, p-coumaric acid, ferulic acid, salicylic acid, rutin, o-coumaric acid, quercitrin, myricetin, quercetin and kaempferol) in apricot variety Betynka. In the process of optimization several types of stationary phase and gradients of mobile phase were tested. For the analysis of real samples guard column Security GuardTM Polar C18 (4 x 2.0 mm, 3 μm) and column Luna Omega Polar (150 mm x 2.1 x 3 μm) were selected. As mobile phase the mixture of ultrapure water acidified with the acetic acid to pH 2.8 and acetonitrile was used. For the analysis the gradient elution with initial isocratic step was used, total analysis time was 17 minutes. The flow rate was 0.6 ml/min and the injection volume 1 μl. The detection was performed by DAD spectrophotometric detector at wavelengths of 254, 260, 280 and 320 nm. Validate...
Optimization of neonicotinoids extraction using nanofibers in sequential injection analysis systém
Zouharová, Monika ; Horstkotte Šrámková, Ivana (advisor) ; Šatínský, Dalibor (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Monika Zouharová Supervisor: PharmDr. Ivana Horstkotte Šrámková, Ph.D. Title: Optimization of neonicotinoids extraction using nanofibers in sequential injection analysis system In this diploma thesis, we tested the use of various nanofibers as sorbents for solid phase extraction of neonicotinoids connected with sequential injection analysis system. Seven types of nanofibers were tested, specifically polyamide (PA6), polycaprolactone (PCL), polyimide (PID) and polydopamine coated polyamide (PA6)coated, polycaprolactone (PCL)coated, polyimide (PID)coated and a combination of polyimide and polycaprolactone (PID/PCL)coated. These nanofibers were produced by electrospinning. The studied nanofibers were placed in the 3D printed holder, which was connected into sequential injection analysis system. UV spectrophotometry was used as a detection method. The substances to analyse were neonicotinoid insectisides. The retention of these analytes was examinated with all seven types of nanofibers. Retention of the analytes on the tested nanofibers depending on their chemical structures and physical-chemical properties was studied in these measurements. The most experiments were performed with polydopamine coated...
Modification of nanofibres for extraction in liquid chromatography
Valachovič, Adam ; Šatínský, Dalibor (advisor) ; Chocholouš, Petr (referee)
Department: Department of Analytical Chemistry Candidate: Adam Valachovič Supervisor: doc. RNDr. Dalibor Šatínský, Ph.D. Title of the diploma thesis: Modification of nanofibers for extraction in liquid chromatography The diploma thesis demonstrates the influence of modifications of polymer nanofibers on their extraction properties for extraction in liquid chromatography. Nanofibers represent a potential sorbent for extraction methods due to their large surface area, which leads to increased capacity of extraction. Another advantage of nanofibers is the possibility to modify their surface resulting in various nanofibers with different extraction properties. In this thesis, the modifications were performed by coating polypropylene nanofibers with a polydopamine layer. The polymerization solution was pumped through a column, in which the nanofibers were placed, using a peristaltic pump connected to the column by a system of tubes. An on-line SPE HPLC method was developed to determine the extraction properties of the modified nanofibers. Chlorogenic acid was chosen as the model analyte, because its extraction is affected by the polydopamine layer. The key parameters of the coating process were optimized, including the weight of the nanofibers, the concentration of dopamine in the polymerization...
Analysis of nutritionally important substances in fruit tree waste products by HPLC
Šírová, Karolína ; Šatínský, Dalibor (advisor) ; Sklenářová, Hana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Karolína Šírová Supervisor: doc. RNDr. Dalibor Šatínský, Ph.D. Consultant: Mgr. Anežka Adamcová Title of Diploma Thesis: Analysis of nutritionally important substances in fruit tree waste products by HPLC This diploma thesis deals with the content of phenolic compounds in various parts of tree of the genus Pyrus. The theoretical part is focused on characterization, biosynthesis, chemical and biological properties of major phenolic compounds in pear-trees and the possibilities of their determination with the use of the latest scientific studies. The experimental part contains an extensive analysis of arbutin, chlorogenic acid, 1,5- dicaffeoylquinic acid, 3,5- dicaffeoylquinic acid and rutin in extracts of leaves, bark, buds, fruits, flowers and wood chip. Developed and validated HPLC-DAD method was used and the total antioxidant activity was determined by FIA method with electrochemical detection. An ASCENTIS Express RP-Amide 150×4.6 mm, 2.7 μm analytical column and gradient elution consisting of organic part of acetonitrile (ACN) and water part with 0,85% phosphoric acid (pH = 2.2) were used for analysis. The detection was performed by DAD detector at wavelengths 220 nm, 327 nm and 354 nm. The...
Application of nanofibrous sorbents for on-line extraction in liquid chromatography
Háková, Martina ; Šatínský, Dalibor (advisor) ; Česla, Petr (referee) ; Urban, Jiří (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Mgr. Martina Háková Supervisor: doc. RNDr. Dalibor Šatínský, Ph.D. Consultant: doc. PharmDr. Lucie Chocholoušová Havlíková, Ph.D. Title of Doctoral Thesis: Application of nanofibrous sorbents for on-line extraction in liquid chromatography A compilation of ten publications is presented in this dissertation thesis. It is focused on the application of nano and microfibrous polymers as a new extracting material in analytical chemistry. This work was based on close cooperation with the Institute for Nanomaterials, Advanced Technologies and Innovation and the Department of Nonwovens and Nanofibrous Materials at the Technical University of Liberec, where the author took part in designing and preparation of these materials. The first part deals with model studies, based on using polyamide, polystyrene and polycaprolactone nanofibers as sorbents for solid phase extraction in classical off-line mode or in on-line column switching system. It solves practical aspects such as orientation and the formation of the fibers in the extraction system, optimization of fabrication factors affecting applicability of the nanomaterials, suitable solvent systems, stability testing and reusability of the microcolumns. The...
Optimization of separation conditions for HPCCC of paclitaxel
Havrlantová, Šárka ; Kučera, Radim (advisor) ; Šatínský, Dalibor (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Šárka Havrlantová Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Name of diploma thesis: Optimization of separation conditions for HPCCC of paclitaxel The aim of this work is a feasibility study of natural substances isolation (in my case it is paclitaxel and its intermediate 10-deacetylbaccatin) using modern technique called High performance countercurrent chromatography (HPCCC) available in Teva in Opava. For this basic research it was necessary to study the literature and test various solvent systems. Chosen solvent systems were then tested together with natural substance in HPCCC, results were processed and discussed. Countercurrent chromatography is considered a modern separation technique based on two immiscible liquids. One of them is called a stationary phase and is held inside the column by centrifugal force, the second liquid is called a mobile phase and is pumped through the column. Then the injected liquid sample is also pumped through the column and depending on distribution coefficients the sample components are either held in the stationary phase or pass through the column and detector into fraction collector. Advantages of this method are e.g. total...
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...

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