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The possibilities of assessment of free fatty acids in food matrix
Brožová, Michaela ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
This bachelor´s thesis has a research character and deals with the possibilities of determination of fatty acids in foodstuffs, mainly focused on dairy products. It starts by overview of general characteristics of lipids and fatty acids. The crucial part of thesis represents summary of the methods, which can be used for determination of fatty acids. A special chapter is devoted to determination of free fatty acids. The isolation of lipids/fatty acids from sample matrix is necessary before the determination itself, classic solvent extraction in various applications or several new extraction techniques, e.g. solid phase extraction or supercritical fluid extraction, can be used for this purpose. After the separation of individual lipid fractions, for which the solid phase extraction and/or thin layer chromatography are usually used in practice, the transformation of fatty acids to derivatives, which are suitable for following analytical determination, is often necessary. Gas chromatography with the flame-ionization or mass selective detection is most often used for determination and therefore fatty acids are converted to substantially more volatile methyl esters. In some special cases high performance liquid chromatography and/or thin layer chromatography can be used.
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New Electrochemical Methods for Determination of Nitro and Oxo Derivatives of Fluorene
Vyskočil, Vlastimil ; Barek, Jiří (advisor) ; Ludvík, Jiří (referee) ; Heyrovský, Michal (referee)
4. Conclusion This Thesis represents a contribution to the search for new analytical methods applicable on environmental and biological samples. The current state- of-art concerning the formation, occurrence, and biological activity of fluorene and its nitro and oxo derivatives was summarized in Chapter 1. Further experimental work was focused on assessment of new approaches in the detection of the studied compounds. Attention was paid mainly to nitrofluorenes, fluorenone and nitrofluorenones, namely 2-nitrofluorene, 2,7-dinitrofluorene, 9-fluorenone, 2-nitro-9-fluorenone, and 2,7-dinitro-9- fluorenone and the possibilities of their determination using polarographic and voltammetric methods. Interactions of calf thymus dsDNA with 2-nitrofluorene and 2,7-dinitrofluorene at the DNA/SPCPE were investigated and subtle DNA damage under conditions of direct DNA-analyte interaction at room temperature and damage to DNA bases under condition of electrogeneration of short-lived radicals of nitrofluorenes at human body temperature were found. The obtained results can be summarized as follows: ● Modern polarographic and voltammetric methods at mercury electrodes developed for determination of trace amounts of 9-fluorenone and 2,7-dinitro-9-fluorenone (and other NPAHs generally) in concentration ranges from 2×10-8 to...
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Development and Application of High Performance Separation Methods in Connective Tissue Analysis
Braun, Martin ; Štulík, Karel (advisor) ; Pacáková, Věra (referee) ; Samcová, Eva (referee)
24 Annotation: This work is concerned with the development and application of high performance separation methods suitable for determination of clinically considerable fragments of collagen and elastin as the most important proteins of connective tissues. For their analyses, various chromatographic and electrophoretic methods have been used, including high performance liquid chromatography (HPLC), capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC). This work has aimed at optimization of the developed and modified analytical separation procedures and methods and their utilization for determination of clinically important markers of connective tissue degradation. The key validation parameters of the analytical methods used in this work were evaluated too, which enabled their comparison with other approaches. One of the most important results of this work is thus high sensitivity, precision, repeatability and robustness of the methods which was found in a number of biological sample types. Successful was also very good HPLC separation of the analyzed cross-links in both collagen and elastin tissues. High performance methods are described which have been suggested and optimized for separation and quantitative determination of pentosidine, pyridinolines and...
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The significance of the analysis of noncholesterol sterols and profile of fatty acids in various pathophysiological states
Vecka, Marek ; Tvrzická, Eva (advisor) ; Zadák, Zdeněk (referee) ; Kazdová, Ludmila (referee)
At present time, there is growing interest in two classes of lipids - sterols and fatty acids, which posses many different roles in living organisms. The concentrations of cholesterol biosynthetic precursors (lathosterol, desmosterol) reflect level of cholesterol biosynthesis, whereas the plasma phytosterol (campesterol, β-sitosterol) concentrations can be used for estimation of fractional absorption of dietary cholesterol. These groups are sometimes called together as noncholesterol sterols. The dissertation thesis dealt with the significance of analysis of noncholesterol sterols and fatty acid profile in various pathophysiological states. The methodology part of the thesis covered some aspects of analysis of these compounds with capillary gas chromatography. We found that for the minor fatty acid analysis, both the type of the column and the software used play an important role. The gas chromatography step contributes by the least part to the total error of the procedure, whereas the effect of other steps (extraction, thin-layer chromatography and methylation process) is more pronounced. The comparison of fatty acid profiles in lipoprotein particles with low and very low density revealed differences, but these differences were highly interindividual. We also found that it is possible to replace the...
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Overview of methods used in plant physiology for primary and secondary compounds estimation
Dlouhý, Lukáš ; Tomášková, Ivana (advisor) ; Čepl, Jaroslav (referee)
This bachelor thesis aims to summarize methods used to prove and isolation substances of primary and secondary metabolism of plants. In introduction I described metabolit path ways leading to creation of metabolites and introduced their definitions. In next chapters I pursued closer description of each group and sub-group of metabolites and specified options of their qualitative analysis. In last part I continued to
outline issues of separation methods, instrumental analysis and finaly to experiments. In conclusion I summarized obtained information generaled comparison of each method or their groups. I estimated the trend of analysis for trees and plants.
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Dehalogenation of Polychlorinated Biphenyls
Bureš, M. ; Pekárek, Vladimír
This work deals with the determination of the thermodynamic stability of di- to nona-chlorinated biphenyls during the dehalogenation process of these compounds in the gas phase by steam in presence of solid copper. The aim of this study is a preliminary calculation of chemical equilibrium in this dehalogenation process, which can be compared with the measured kinetics data, obtained during simulation of the technologic process. The work is connected with our previous studies, carried out with dehalogenation of polychlorinated benzenes and polychlorinated phenols.
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Determination of selected chemical parameters of fruits of modern gooseberry varieties
Javorská, Kateřina ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
Diploma thesis deals with determination of individual chemical parameters contained in modern varietes of gooseberries (Grossularia uva-crispa). The theoretical part is focused on the botanical characteristics of the plant, a description of selected varietes, chemical composition and food utilization fruits. The second half of the theoretical part is devoted to the characterization of selected nutritional parameters and methods for determination of total anthocyanins, phenolic compounds, vitamin C and antioxidant activity. Total of 17 varietes of gooseberries, which come from growers Vondráček and the Research and Breeding Institute of Pomology Holovousy Ltd. were analyzed in the experimental part. pH differential method was used to determination total monomeric anthocyanins. Total content of polyphenols were determined by using the Folin-Ciocalteu reagent. Next was determined content of vitamin C in all varieties by HPLC and was evaluated the total antioxidant aktivity using radical DPPH. In conclusion, individual varieties of gooseberries were compared by the contents of the determined chemical parameters.
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Applications of chiral and achiral chromatography in pharmacology and toxicology
Chytil, Lukáš ; Slanař, Ondřej (advisor) ; Bultas, Jan (referee) ; Coufal, Pavel (referee)
Development and validation of methods for analysis of several drugs or their metabolites are decribed in this thesis. The document is presented as a commentary to the original papers, which were published in peer reviewed journals. Discussion on the optimization of each method is presented and covers also method development and influence of preanalytical aspects. Additionally, examples of the application of the developed methods in clinical pharmacology and toxicology are shown. This dissertation consists of three parts: enantiomeric determination of tramadol and its metabolite, determination of some antihypertensive drugs, and qualitative analysis of benzodiazepines. Development of a method for chiral analysis of tramadol and its desmethylated metabolite O- desmethyltramadol (ODT) in human urine and plasma is described in the first part of the thesis. Tramadol is a centrally acting analgetic drug, which is used as racemate in clinical practise. Each enantiomer displays different binding properties for various receptors: (+)-tramadol preferentially inhibits serotonin reuptake while (-)-tramadol mainly inhibits noradrenalin reuptake. (+)-tramadol is considered 10-times more potent than (-)-tramadol. Major active metabolite (ODT), which is considered to be the main agent responsible for the...
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Determination of aminoglutethimide using HPLC-ED on carbon pastes
Vlachová, Karolína ; Šestáková, Ivana (referee) ; Zima, Jiří (advisor)
In this thesis, the determination of AGT, sooner used as anticancer drug, especially for the treatment of breast cancer in postmenopausal women or for the treatment of prostate cancer, by high performance liquid chromatogramy with UV spectrophotometric detection (HPLC-UV) and electrochemical detection (HPLC-ED) on carbon paste electrodes (CPEs) was studied. CPEs were prepared from glassy carbon microspheres and different pasting liquids - routinely used mineral oil (CPE-MO) and less commonly used tricresylphosphate (CPE-TCP) and silicone oil (CPE-SO). The concentration dependences of AGT were measured by HPLC-UV with detection wavelength 242 nm, by HPLC-ED with a working potencial of +1,3 V for CPE-MO and + 1,1 V for CPE-TCP in mobile phase containing phosphate buffer (pH 4) and methanol 50:50 (v/v). The following limits of detection were achieved - 3,6. 10-7 mol.l-1 for UV spectrophotometric detection, 2,5. 10-7 mol.l-1 for electrochemical detection with CPE-MO and 9,7. 10-7 mol.l-1 for electrochemical detection with CPE-TCP. AGT was also determined in model samples of urine. With HPLC-UV it was not possible to detect AGT, because of the interferences of other compounds. With HPLC-ED on CPE-MO the limit of detection 5,2. 10-7 mol.l-1 AGT was achieved. KEY WORDS Aminoglutethimide HPLC with UV...
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Determination of phosphates in waters and characterization of their negtive effects on water ecosystem
Novotný, Radek ; Komendová, Renata (referee) ; Sommer, Lumír (advisor)
This bachelor thesis is focused on the negative effects of phosphates in natural waters and their methods of determination. The first part is characterized by a negative impact on natural water and there are characterized the problems associated with eutrophication, development of cyanobacteria and algae and the resulting potential health risks. The second section describes the methods by which phosphates can be determined. The work highlights the particular spectrophotometric methods such as molybdophosphoric acid, vanadomolybdophosphoric acid, wolframophosphoric acid, phosphomolybdenum blue and methods with some basic dyes such as rhodamine B, rhodamine 6G, malachite green and crystal violet. There are also mentioned methods, which are used less frequently, but they are relatively sensitive, such as AAS, AES, LC-ICP-MS and next such as chromatographic, electrochemical and enzymatic methods. Finally, work mentions the possibility of using automatic techniques such as FIA or CFA, which are suitable for routine and frequent determination, often using the spectrophotometric methods, but not only these.
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