|
|
Study of geographical authenticity of moravian red wine
Bidmonová, Karolína ; Punčochářová, Lenka (referee) ; Pořízka, Jaromír (advisor)
This bachelor thesis discusses the possibility of using analytical methods to determine the elemental profile of wine and to detect phenolic substances in wine. The theoretical part describes the Czech and Moravian subregions, chemical composition of wine, authenticity and methods of assessing the authenticity of wine. The next part contains a brief description of the analytical methods that were used in the experimental part. The experimental part deals with the determination of the elemental profile of wine by mass and optical emission spectrometry, the determination of phenolic substances by high performance liquid chromatography, the determination of antioxidant activity and the total content of phenolic substances. For the purpose of classifying wine samples into groups, multidimensional statistical methods (cluster analysis, principal component analysis, analysis of variance and discriminant analysis) were used to separate the groups according to geographical origin.
|
|
|
Influence of the Application of Lignite on the Distribution of Organic Carbon in Soil
Širůček, David ; Záhora, Jaroslav (referee) ; Kalina, Michal (advisor)
This diploma thesis is focused on optimization of sequential chemical fractionation method to humeomics in order to be useful for determination of organic matter content and distribution and also organic elements in soil. Subsequently, the optimized method is used to assess the efect of lignite application as soil support on these soil characteristics. For these purposes, there were three source matrices of organic matter (lignite, soil and annual soil extraction after lignite application) fractionated by sequential chemical analysis. In parallel, these samples were also fractionated by classic alkaline extraction to obtain the so-called extractable fraction of organic matter (NOM). Individual fractions from sequential chemical fractionation as well as NOM samples were characterized by methods of elemental analysis (determination of organic elements), thermogravimetry (contents of ash, organic matter and moisture) and FTIR spektrometry (structural analysis). The results obtained from a large range of data from all humeomics fractions and NOM fractions showed that the method of sequential chemical fractionation gives higher yields of organic matter compared to classic alkaline extraction. Another indisputable advantage is the fact that the obtained fractions divided according to solubility and strenght of binding to soil inorganics can be better characterized by physical-chemical methods, which provides more detailed information about soil organic matter. The results of the work also show that in order for lignite as a support substance to significantly affect soil properties, a longer time, multiple sampling and repetition of individual fractionations would be needed.
|
|
|
Quantification of food waste in municipal waste and the possibility of processing this waste
Orságová, Marie ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
The theoretical study of anaerobic digestion is designed to predict the amount of biogas in food waste. The theoretical part characterizes the processing of biodegradable waste as well as the use of biogas and the calculation method for determining biogas production. In the experimental part, the analytical technique of inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine minerals (K, Ca, P, Mg, Na, Zn, Cu, Fe and Mn) in food waste, as well as elemental analysis for carbon, oxygen, hydrogen and nitrogen determination. This thesis provides a simplified model that predicts the amount of produced biogas and could be used for further feasibility studies, such as bioreactors dimensioning. The method can be used for different starting materials and repeated for other similar applications in an effort to extend anaerobic digestion systems as a source of clean energy.
|
|
|
Use of analytical methods and chemometry to verify the geographical authenticity of honey
Marková, Lucie ; Křikala, Jakub (referee) ; Diviš, Pavel (advisor)
The teoretical part of this bachelor thesis is focused on the process of producing the honey by bees, its composition and means of its adulteration or ways to detect substandard products. The experimental part describes methodes, which were used to observe the samples. Sacharides, organic acids, mineral content, the amount of dry matter, titration acidity and conductivity were meassured. Obtained data were used for differentiation the Czech and foreign honey. The result of the statistical analysis shows the calcium, copper and glucose content are suitable paramteres to differentiate the Czech honey from that externals. Theese parameters could be used to distinguish the two different geographical origin of honey. Nevertheless, the total evaluation seems to be insufficient for differentiation these two groups. The efficiency could be icreased by the including more samples for analysis, or meassuring more parameters. Finally, some of the parameters were used for quality control of honey.
|
|
|
Use of Hofmeister series of ions for fractionation of soil humic acids
Kebabová, Mona ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
The bachelor thesis deals with the study of the structure and behaviour of humic acids (HA) in the presence of salts of the Hofmeister series of ions. Haplic Luvisol and sodium humate extracted from it were characterized by elemental analysis (EA) and thermogravimetric analysis (TGA) to determine the percentage of elements and ash. Fourier Transform Infrared Spectroscopy (FT-IR) was used to determine the functional groups in the sample. UV-VIS was used to investigate the effect of the Hofmeister salts. From its results were calculated the absorption coefficients EET/EBZ, E2/E3, E2/E4 and E2/E6, and the specific absorbance values SUVA254 and SUVA280. Other methods like Dynamic Light Scattering (DLS) and fluorescence spectroscopy were used to better understand HA's structure. The main goal of this bachelor thesis was to find a simple experimental method based on which we would be able to study supramolecular associations of HK, which are preferentially linked to the formation of weak intra- and intermolecular interactions in aqueous solutions.
|
|
|
Properties of aminoclay complexes and biologically active substances
Dušek, Jakub ; Pekař, Miloslav (referee) ; Mravec, Filip (advisor)
This paper builds on previous research of aminoclay complexes in undergraduate studies. Theoretical part deals with study of current problems of aminoclay complexes with bioactive substances and the choice of substances for complexing with aminoclay. The experimental part consists of preparation of aminoclay complexes with selected bioactive agents at various concentrations. Verification of binding of bioactive agents to the aminoclay matrix was performed by Elemental Analysis (EA) and Fourier-transform infrared spectroscopy (FT-IR). For finding of the bound amount of bioactive substance were used the Ultra Performance Liquid Chromatography (UPLC®) and analysis of the cytotoxic properties of the formed complexes by used by the MTT assay. The main motivation of this study is to create new complexes with improved characteristics that would replace existing forms of substances used in pharmaceutical and biomedical applications.
|
|
|
Determination of the basic physical and chemical parameters of fruit juice from aronia
Zídková, Anežka ; Jurečková, Zuzana (referee) ; Diviš, Pavel (advisor)
Theoretical part of bachelor´s thesis contains basic information about aronia (Aronia melanocarpa) and examples of their use. There is a description of analysed substances, which are contained in aronia berries, and their importance for human organism. Experimental part is focused on determination of minerals, saccharides and vitamin C in aronia juices, syrups, nectar and aronia wine. Elements were determined by inductively coupled plasma optical emission spectrometry. Liquid chromatography was chosen for analysis of saccharides and vitamin C. All of analysed products are significant sources of macroelements. The highest concentrations of elements were determined in the sample named Aroniový skorosirup, which was sugared by vaporized apple juice. Fructose and glucose were contained in all products. Sucrose was only in products which were sugared. The amount of vitamin C was lower in consequence of pasteurization and storage.
|
|
|
Nutritional composition of different type of milk
Viznerová, Veronika ; Punčochářová, Lenka (referee) ; Diviš, Pavel (advisor)
The aim of this bachelor’s thesis was to compare selected methods of milk treatment for elementary analysis using the ICP-OES technique. Certified reference material ERM®-BD150 was used to validate the method, which was treated by mineralization, the addition of reagents and dispersion. The highest calcium yield during validation was determined to be 90,6 ± 8,6 % with the addition of Triton X-100 reagent. In the potassium analysis, the highest yield was determined to be 89,5 ± 5,2 % by wet decomposition. The highest yield of magnesium was determined to be 120,1 ± 1,1 % after microwave decomposition. Furthermore, the highest yield of sodium was determined to be 104,4 ± 4,8 % by wet decomposition and the highest yield of phosphorus was determined to be 98,6 ± 4,5 %. Based on the validation results, suitable methods were selected for the analysis of real milk samples (wet decomposition, acid dispersion, addition of Triton X-100 reagent). Samples of fresh cow's, goat's and sheep's milk from domestic breeding were used for the analysis. The highest concentrations of most elements were determined in goat 's milk, namely calcium to 1 733 ± 126 mg.kg-1, potassium to 1 840 ± 39 mg.kg-1, magnesium to 252 ± 77 mg.kg-1, copper to 1,41 ± 0,56 mg.kg-1, manganese to 0,54 ± 0,26 mg.kg-1 and zinc to 7,98 ± 1,33 mg.kg-1. The highest concentrations of sodium in sheep's milk were set at 515 ± 90 mg.kg-1, phosphorus at 1 440 ± 100 mg.kg-1 and zinc at 7,98 ± 1,33 mg.kg-1. The most iron was found in cow's milk, namely 5,27 ± 1,59 mg.kg-1. For ICP-OES analysis, the use of an acid dispersion appears to be the best method of sample preparation, as the concentrations of the measured elements were the highest. However, only macroelements and zinc were measured reliably. For the determination of other biogenic elements, it would be more appropriate to choose a more sensitive technique or preconcentration of the analyte in the sample.
|
|
|
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.
|
|
|
Use of Hofmeister series of ions for fractionation of soil humic acids
Kebabová, Mona ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
The bachelor thesis deals with the study of the structure and behaviour of humic acids (HA) in the presence of salts of the Hofmeister series of ions. Haplic Luvisol and sodium humate extracted from it were characterized by elemental analysis (EA) and thermogravimetric analysis (TGA) to determine the percentage of elements and ash. Fourier Transform Infrared Spectroscopy (FT-IR) was used to determine the functional groups in the sample. UV-VIS was used to investigate the effect of the Hofmeister salts. From its results were calculated the absorption coefficients EET/EBZ, E2/E3, E2/E4 and E2/E6, and the specific absorbance values SUVA254 and SUVA280. Other methods like Dynamic Light Scattering (DLS) and fluorescence spectroscopy were used to better understand HA's structure. The main goal of this bachelor thesis was to find a simple experimental method based on which we would be able to study supramolecular associations of HK, which are preferentially linked to the formation of weak intra- and intermolecular interactions in aqueous solutions.
|
guest ::
