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Use of thin layer chromatography for fractionation and characterization of organic matter isolated from alginite
Solanský, Pavel ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
This diploma thesis is focused on the study of structure and physicochemical properties of organic fractions of humic substances, which were obtained by the method of thin-layer chromatography. Humic substances, which were used in this study, were isolated from a sample of Slovak alginite based on the procedure of the International Humic Substances Society (IHSS). The following analytical techniques were selected for the characterization of isolated humic substances: thermogravimetric and elemental analysis, molecular absorption spectroscopy (UV/Vis), Fourier transform infrared spectroscopy (FTIR) and steady-state fluorescence spectroscopy. Each organic fraction of humic substances were characterized by molecular absorption spectroscopy (UV/Vis) and steady-state fluorescence spectroscopy. Using steady-state fluorescence spectroscopy, humic substances were found to be composed of fluorophores of humic and non-humic (protein) character. Organic fractions corresponding to the humic fluorophores were characterized by a higher content of oxygen substituents on the aromatic nukleus, a higher degree of aromaticity and also a higher molecular weight. The aim of this diploma thesis was to design and optimize the process of organic matter fractionation for the purpose of detailed understanding of the structure and properties of humic substances, which were isolated from the sedimentary rock alginite. Based on this, the practical applicability of the thin layer chromatography method to significantly reduce the molecular heterogenity of the studied humic substances was evaluated.
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Characterization of plant-based component of selected foodstuffs using techniques of molecular biology and instrumental methods
Tomíšek, Martin ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The aim of this work was to compare authenticity analysis in selected food products with fruit component by using, instrumental and molekular methods. Particularly, the presence of blueberries in fruit–based foodstuffs was verified. The theoretical part is focused on the characterization, chemical composition and botanical classification of blueberries (European blueberry and Canadian blueberry). It also contains an overview of instrumental and molecular diagnostic methods that can be used for the analysis of these fruits. The experimental part focuses on the selection of a suitable method of DNA isolation, and primers for the detection of blueberries in commercial products. DNA analysis was performed by qPCR and HRM analysis. In the experimental part, DNA was isolated in sufficient quality for PCR and the presence of blueberries in foodstuffs was verified by qPCR. Using HRM analysis, we were able to differentiate between bilberry (Vaccinium myrtillus) and blueberry (Vaccinium corymbosum) in control samples and in some commercial products. Certain phenolic acids and some flavonoids specific for blueberries were detected by HPLC. The total content of polyphenols and flavonoids was determined by UV / VIS spectrophotometry.
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Characterization of humic substances isolated from natural waste treated by vermicomposting process
Marková, Kamila ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis deals with the study of humic substances isolated from vermicompost natural waste through spectrometric methods. The aim of this thesis is to study physicochemical properties of the humic substances through modern instrumental techniques such as molecular absorption spectroscopy in the ultraviolet and visible regions of electromagnetic radiation (UV/Vis), infrared spectroscopy with Fourier transformationn (FTIR), elemental analysis (EA), thermogravimetric analysis (TGA) and inductively coupled plasma emission (ICP OES). A research focused on basic information about the humic substances was developed in the theoretical part. A description about their distribution or structure was made and also their utilization in medicine, industry or ecology. Then, methods, which are used for study of the humic substances, were described as well. An essential part of the thesis was isolation of humic and fulvic acid from the vermicompost natural waste. Absorption coefficients were calculated from the measured UV/VIS spectrum which served to following characterization of HK and FK. FTIR spectrum was used to determination of functional groups of studied HL. An area of biogenic elements was specified using the elementary analysis. Total amount of studied trace elements was determined with with the help of ICP-OES.
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Developement and validation of method for ferulic acid isolation from wheat bran
Nábělek, Jakub ; Obruča, Stanislav (referee) ; Pořízka, Jaromír (advisor)
This master thesis deals with an optimization of processes of isolation of ferulic acid from wheat bran. Process of isolation based on alkaline hydrolysis from the substance and its adsorption was tested. In the theoretical part were described wheat bran, adsorption proces and used methods. For adsorption were tested five types of adsorbents. Especially these adsorbents: activation carbon (2,53 ± 1,16 mg.l-1), Amberlyst A-21 (105,73 ± 11,87 mg.l-1, Amberlit XAD-16 (241,55 ± 10,42 mg.l-1), Amberlit IRA-900Cl (5,90 ± 0,68 mg.l-1) and Amberlit IRA-96 (189,16 ± 6,49 mg.l-1). As the most efficient adsorbent was determine Amberlit XAD-16. The whole process has underwent detailed optimization in order to maximize the purity of the final product. The isolate was characterized by HPLC and FTIR techniques for ferulic acid and related phenolic acids. Based on FTIR analysis was discovered that the isolate was contamined by proteins. A purification procedure based on deproteination of the raw material before the hydrolysis itself was proposed. As the ultimate solution that eliminated the presence of proteins in the isolate was determine ultrafiltration with capture of molecules with Mw > 10 KDa. Ferulic acid yield from one kilo of wheat bran was 1,00 ± 0,22 g.
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Physicochemical and structural analysis for characterization of native and modified humic acids
Solanský, Pavel ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis is focused on structural and physicochemical characterization of native and methylated humic acid. These samples of humic acids, which were isolated from oxidized brown coal Leonardite, were characterized by thermal and spectrometric methods. The following analytical techniques were selected to determine the structural and physico-chemical changes between native and methylated humic acid: thermogravimetry (TGA), elemental analysis (EA), molecular absorption spectroscopy (UV/Vis), Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy and last but not least nuclear magnetic resonance (13C NMR). The aim of this bachelor thesis was to find the differences in the structure of selected humic acids and also to verify the suitability of the techniques, which were used to characterize these biocolloid substances.
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Preparation and characterization of hydrogels with diffusion gradient
Tvrdoňová, Anna ; Pekař, Miloslav (referee) ; Smilek, Jiří (advisor)
The presented bachelor thesis deals with the preparation and further characterization of hydrogels with a diffusion gradient. The aim of the thesis is a literature research on the issue of hydrogels with a diffusion gradient, and a selection of a suitable method for its preparation. Moreover, conducted pilot experiments lead to the characterization of the properties of the prepared systems, especially with regard to proving the gradient structure of hydrogels. The performed evaluation was based on visual observation, determination of transport, and viscoelastic properties. In addition, a simple method consisting of weighing the prepared hydrogels was used. Hydrogels were compared depending on the choice of crosslinking agent, its concentration, and crosslinking time. Gradient hydrogels based on polysaccharide sodium alginate were prepared. The results suggest that by selecting the concentration of the crosslinking agent, as well as the crosslinking time, the final properties (viscoelastic and transport) of the hydrogels can be adjusted to the desired values. In the discussion of the results, we propose steps for a more comprehensive view of the issue and providing options for the following research.
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Determination of content of selected nonsteroidal antiphlogistic – Ibuprofen in drugs using UV/Vis and FTIR spectrometry
Lindovský, Jiří ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
The main aim of bachelor thesis was to validate the content of the nonsteroidal antiphlodstic in drugs using spectrometric methods and subsequent comparison of results. Specifically, the thesis is focused on Ibuprofen, which is used mainly as analgesic and antipyretic. This substance was chosen for its significant ability of absorbing electromagnetic radiation in ultraviolet and infrared regions of spectra. For this purpose, various generics were selected and analyzed by molecular absorption spectrometry (UV/Vis) and infrared spectrometry with Fourier transform (FTIR). Very important factor influencing chemometric properties of the obtained results was optimalization of the spectrometric methods. After designing the working procedure, sample solutions were prepared from Ibuprofen-containing dosage forms using suitable solvent and these samples were analyzed spectrometrically. The content of Ibuprofen in individual samples was calculated from the measured UV/Vis and FTIR spectra using method of standard addition. The results show that infrared spectrometry seems to be more suitable method for determining the Ibuprofen content. Nevertheless, it should be noted that the choice of a suitable extractant is very important step in the determination. The information obtained from this bachlor’s thesis could be used in future routine inspections and monitoring of drugs.
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Physicochemical characterization of soil humic substances isolated from modal brown soil
Churina, Iuliia ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis deals with the physicochemical characterization of soil humic substances isolated from brown earth modal based on the international IHSS procedure. Humic substances are organic compounds occurring in soil and have a significant influence on soil processes and properties. The aim of this work is to obtain detailed information on the physical and chemical properties of humic substances such as mean molecular weight (Mr), spectral characteristics, elemental composition and thermal stability. Soil humic substances samples were characterized by thermal techniques such as thermogravimetric (TGA) and elemental analysis (EA). Different instrumental methods such as UV/Vis spectrometry, infrared spectrometry and fluorescence spectrometry were used to analyze the samples. The results of this work can contribute to a better understanding of soil processes and properties, which can lead to improved agricultural production and environmental protection.
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Preparation and characterization of hydrogels with diffusion gradient
Tvrdoňová, Anna ; Pekař, Miloslav (referee) ; Smilek, Jiří (advisor)
The presented bachelor thesis deals with the preparation and further characterization of hydrogels with a diffusion gradient. The aim of the thesis is a literature research on the issue of hydrogels with a diffusion gradient, and a selection of a suitable method for its preparation. Moreover, conducted pilot experiments lead to the characterization of the properties of the prepared systems, especially with regard to proving the gradient structure of hydrogels. The performed evaluation was based on visual observation, determination of transport, and viscoelastic properties. In addition, a simple method consisting of weighing the prepared hydrogels was used. Hydrogels were compared depending on the choice of crosslinking agent, its concentration, and crosslinking time. Gradient hydrogels based on polysaccharide sodium alginate were prepared. The results suggest that by selecting the concentration of the crosslinking agent, as well as the crosslinking time, the final properties (viscoelastic and transport) of the hydrogels can be adjusted to the desired values. In the discussion of the results, we propose steps for a more comprehensive view of the issue and providing options for the following research.
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Use of thin layer chromatography for fractionation and characterization of organic matter isolated from alginite
Solanský, Pavel ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
This diploma thesis is focused on the study of structure and physicochemical properties of organic fractions of humic substances, which were obtained by the method of thin-layer chromatography. Humic substances, which were used in this study, were isolated from a sample of Slovak alginite based on the procedure of the International Humic Substances Society (IHSS). The following analytical techniques were selected for the characterization of isolated humic substances: thermogravimetric and elemental analysis, molecular absorption spectroscopy (UV/Vis), Fourier transform infrared spectroscopy (FTIR) and steady-state fluorescence spectroscopy. Each organic fraction of humic substances were characterized by molecular absorption spectroscopy (UV/Vis) and steady-state fluorescence spectroscopy. Using steady-state fluorescence spectroscopy, humic substances were found to be composed of fluorophores of humic and non-humic (protein) character. Organic fractions corresponding to the humic fluorophores were characterized by a higher content of oxygen substituents on the aromatic nukleus, a higher degree of aromaticity and also a higher molecular weight. The aim of this diploma thesis was to design and optimize the process of organic matter fractionation for the purpose of detailed understanding of the structure and properties of humic substances, which were isolated from the sedimentary rock alginite. Based on this, the practical applicability of the thin layer chromatography method to significantly reduce the molecular heterogenity of the studied humic substances was evaluated.
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