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Use of DGT technique for mercury determination in food liquid flavorings
Habartová, Aneta ; Reichstädter, Marek (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with varification of the use of the diffusive gradient in thin films technique (DGT) for food analysis. It focuses on testing a new type of sorption gel containing Purolite S924 as well, commercially available for mercury determination in food liquid flavorings. Theoretical part contents of characteristics and production of fish sauces are described analytical methods for mercury determination and DGT technique. Experimental part focused on optimization of preparation of sorption gel and validation DGT techniques for mercury determination in fish sauces. After validation DGT technique was successfully used for analysis real samples of fish sauces.
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Determination of selected metals in unconventional fruit species
Křížová, Soňa ; Dočekalová, Hana (referee) ; Diviš, Pavel (advisor)
The aim of this diploma thesis is determination of selected metals in unconventional fruit species, specifically in cornelian cherry (Cornus mas), sea buckthorn (Hippophae rhamnoides) and medlar (Mespilus germanica).There is informationabout 16 analysed metals – As, B, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Sn, Pb, V, Zn. There are described analytical techniques for elemental analysis and methods for destruction biological material. Samples for analysis are prepared by using microwave mineralization and ICP-MS for detection. This is described in the experimental part of the diploma thesis. Analysis confirmed that unconventional fruits are rich sources of trace elements.
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Determination of basic analytical parameters of paprika of different geographic origin
Cagáňová, Linda ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
The aim of this bachelor thesis was to determine the basic analytical parameters of paprika of different geographic origin such as ASTA colour, pH, moisture content and ash. The theoretical part primarily focuses on the characteristic of paprika, it´s division, the chemical composition and the production of ground red pepper. It also deals with spice issues, it´s division, meaning in and storage. In the experimental part there are outlined the individual procedures of determination of parameters (ASTA, pH, moisture, ash) of ten samples of ground red pepper. ASTA values ranged from 80 – 175 ASTA units. Analysis of pH showed that all samples of pepper extracts showed an acidic pH with value around 5. The total moisture and ash content in the samples was 8 – 15 % and 5 – 7 %.
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Analysis of VOC Frankovka wines originating in the Modré hory region
Horáková, Lenka ; Machát,, Jiří (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the chemical characterization of Frankovka red wines and the possibility of using chemical analysis of wines to distinguish Frankovka wines from VOC Modré hory from other Frankovka wines from the Moravian wine region. The theoretical part describes viticulture in the Czech Republic, the characteristics of the Frankovka variety and the wine classification system in the Czech Republic. The next part describes in detail the association VOC Modré hory, the red wine technology and the use of chemometry for wine authentication. The experimental part deals with the determination of the elemental profile of wines by ICP-MS and ICP-OES methods, analysis of selected phenolic substances by HPLC-MS and analysis of organic acids by IC. Furthermore, the analysis of the aromatic profile of wines was performed using the technique HS-SPME-GC-MS and the total content of phenolic substances in wines was determined by the MAS method. A total of 24 wine samples were analyzed, where 12 samples came from VOC Modré hory and another 12 wines came from other Moravian wine regions. Statistical analysis techniques (Mann-Whitney U-test and PCA) were used to classify wine samples into groups in order to separate wines from VOC Modré hory and other wines from other Moravian regions. The results of this work showed that with the help of chemical analyzes and statistical techniques it was possible to distinguish wines from VOC Modré hory from other wines from the Moravian wine region.
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Studying the authenticity of coffee of various geographical origins
Flegr, Šimon ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This diploma thesis researches coffee authenticity problematice, mainly focusing on the authenticity of geographic origin. In the theoretical part of this work, botanical classification is described as well as production technology and processes. The work also includes chemical composition of coffee, describing the major components and changes during production phases. It describes major production areas of the world, in terms of general description and brief history. Problematics with coffee fraud and its identification are also described. Theoretical part also includes general geological description of 17 studied coffee growing regions. Experimental part is devoted to trace amount analysis of selected elements and volatile compounds. The element analysis was conducted using mass spectrometry or optical emission spectrometry, volatile compounds were determined using gas chromatography combined with mass spectrometry detection. Results were statistically described and analyzed, resulting in several discrimination models based on geographic origin.
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Content of toxic and esential elements in bio foodstuffs and their comparing with ordinary foodstuffs
Kohoutková, Nina ; Diviš, Pavel (referee) ; Vitoulová, Eva (advisor)
The aim of this study is to determine the content of toxic and essentials elements in samples of nuts and seeds produced by ecologic agriculture and to compare results with nuts and seeds from conventional agriculture production. These nuts and seeds can be bought in the Czech market (except bio pine nuts, bio pecan nuts and bio pistachios). The amount of elements was analysed using inductively coupled plasma mass spectrometry after previous digestion of samples using microwaves. This study summarizes the main physiological functions of toxic and essentials elements. Results were also compared with another studies. It does not results from all measured amounts of all essential elements, that bio nuts and seeds have higher amounts of these elements; however, all amounts of toxic elements in bio nuts and seeds are lower than in the no-bio ones. For more precise results it would be necessary to measure more samples.
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Comparison of extraction methods for agriculture soil elemental analysis
Štursa, Václav ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This bachelor thesis handles with optimization of preparation process of soil samples from vineyards for elemental analysis performed by ICP-MS. First part of the thesis deals with element analysis and its usage in agrotechnics and viticulture, description of toxic and nutrition properties of individual elements and legislation defining appropriate concentration limits of elements in agricultural land. Next part describes commonly used methods for elemental analysis such as AES, AAS, roentgen fluorescence spectrometry and ICP-MS. Finally, sampling methods and methods for sample preparation such as digestion and extraction are described. Experimental part follows up comparison of selected extraction methods (2M HNO3 extraction, temperature assisted 2M HNO3 extraction, aqua regia extraction and microwave-assisted digestion using mixture of HNO3 and H2O2). These methods were applied on certified reference materials. Extracts were analysed by ICP-MS technique Best results were achieved by 2M HNO3 extraction. This extraction method was subsequently applied on real soil samples from vineyard.
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Study of utilization of waste material from the food industry for the removal of metals from waste waters
Křikala, Jakub ; Obruča, Stanislav (referee) ; Diviš, Pavel (advisor)
In this bachelor thesis is discussed the potential use of the marc from the wine production for the removal of metals from wastewaters. Marc containing stems, peels and seeds without any prior chemical treatment were homogenized and rinsed with distilled water to remove soluble impurities. IR spectrometry was used for characterization of the major functional groups responsible for the adsorption of metal ions. The experimental part of this work consisted of the assessment of the optional pH value for adsorption of copper and the maximum adsorption capacity of the used material in column and batch method. The results show that the optional pH values for adsorption of copper were in the range pH 3 – 4. Maximum adsorption capacity were calculated form adsorption isotherms by applying the Langmuir model and found to be 0,260 4 mg/g Cu at a column method and 1,246 2 mg/g Cu after 30 minutes the batch adsorption method. Further, it was experimentally demonstrated that the adsorption of copper in addition to the pH depends also on the initial copper concentration in the solution, contact time and other parameters whose optimization would achieve greater adsorption capacity of the referred material. The results indicate that the marc from the wine production have good potential form removing metals from wastewaters by adsorption.
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Utilization of waste from the food industry for wastewater treatment
Nedvědická, Lucie ; Obruča, Stanislav (referee) ; Diviš, Pavel (advisor)
This bachelor thesis disserts about options and issues how to utilize waste from the food industry for wastewater treatment contaminated with heavy metals. The theoretical part describes the general characteristics of heavy metals, as well as the permissible and limit values of these heavy metals in waste water. Furthermore, it is described in this document which chemical methods can be used in order to remove heavy metals from wastewater. This thesis also deals with methods how to analyze the adsorbed amount of sorbed substance, means by using AAS, AFS, AES, MS and ICP – OES methods. At the end of the theoretical part, the issues of the different wastes from the food industry are dealing with and their adsorption ability. In the experimental section it was investigated the tea waste utilization in order to eliminate copper ions from waste water. It has been tested mainly the effect of pH on the adsorption of copper onto tea waste and maximum possible adsorption capacity onto tea waste. The pH optimum for the sorption of cooper from solution onto tea waste was within range 5-6 and the maximum possible adsorption capacity 0,0336 mmol•g-1 was determined. The results indicate that the tea waste could be used as a suitable adsorbent for the purification of waste water, mainly due to good availability, low cost and good adsorption ability of heavy metals.
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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.
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