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Analysis of czech garlic varieties
Fähnrichová, Nikola ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This master thesis deals with analysis of Czech garlic varieties in comparison with two varieties from abroad. Alliin and carbohydrates were determined by high performance liquid chromatography with diode-array detector or evaporative light scattering detector. Crude proteins were calculated from total content of nitrogen that was determinated by Kjeldahl method. Elementary analysis was performed by inductively coupled plasma optical emission spectrometry. In theoretical part of this thesis is describes botanical characterization and cultivation of garlic, chemical composition of garlic, especially groups of substances which were analysed in this thesis. Principle of used methods is described too. The experimental part of this work deals with sample and calibration solution preparation and process of analysis. Obtained results from analysed substances are summarized in the tables, discussed and compared with results of analysis of other authors. Between Czech and Spanish/Chinese garlic are slight differences. Garlics contain 24,66 g/kg dry weight of alliin. Content of crude proteins in Czech garlic is comparable to Chinese garlic but the Spanish garlic has just half of amount crude proteins. Elementary analysis also includes significant differences. Czech varieties contain higher amount of phosphorus, iron and zinc. On the contrary, content of potassium in foreign garlic is higher than in Czech Republic and the analysed amount is 15 g/kg dry weight.
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Elemental analysis of cheese with white mold on the surface
Pavlechová, Alžbeta ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
This Master's thesis deals with elementary analysis of cheeses with white mold on the surface. Theoretical part describes general characteristics of cheese, classification of cheeses, their nutritional aspects and characteristics of cheeses with white mold on the surface. Large part is focused on description of mineral substances selected for analysis. At the end of the theoretical part, the Kjeldahl method and emission spectrometry with inductively coupled plasma (ICP-OES) were described. Experimental part deals with preparation of samples, approach of analysis and processing of measured results. Eleven samples of cheeses were used for analysis. These samples were from Czech Republic, France and Slovak Republic. Kjeldahl method was used to determine protein contents and ICP-OES was used for elemental analysis. The results were compared to each other and also with results from other studies. Subsequently, they were statistically processed and evaluated in the final part.
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Elemental analysis of the different varieties of elderberry
Ješková, Kristýna ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
This work deals with the elemental analysis of different elderberry (Sambucus nigra L.) cultivars. In the theoretical part the botanical characteristics of elderberry, including its extension and places of occurrence, the possibilities of collecting the various parts of the elderberry and its use in food and cosmetics is described. A large part is devoted to the occurrence and characteristics of minerals in food, and to the methods that are suitable for elemental analysis and decomposition of biological material. The aim of the experimental part was to analyze different cultivars of elderberry and juice made from this cultivars, and to determine concentration of selected elements (Zn, Mn, Fe, Mg, Cu, P, Ca, Na and K) using ICP–OES. The total amount of 24 cultivars was analysed from which 6 varieties were harvested in two different seasons in 2011 and 2013. Measured concentrations of elements in different varieties of elderberry were mutually compared using statistical methods. The differences between the content of elements in fruits and juice, obtained by pressing the fruit, and the effect of seasonal conditions on the content of elements in the fruit juice from different elderberry cultivars were studied.
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The study of various methods of preparation of the milk sample for milk analysis by ICP-OES technique
Kaňová, Veronika ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
The theoretical part of the thesis deals with the chemical composition of cow’s milk, with the description of chosen methods of sample pretreatment and with the description of the used technique ICP-OES. The practical part is aimed at individual preparations of samples and at analysis of chosen chemical elements (Ca, Na, K and Mg). Milk is a really complicated polydisperse system, that’s the reason why the preparation of samples with milk is very important step before the measurement itself. In addition to accuracy choosing the sample adjustment method, other factors such as time, work intensity, or cost need to be considered when. In the thesis a comparison of four selected methods of sample preparation was made: direct analyse of milk, dilution with addition of Triton X-100, wet microwave ashing and destruction of matrix with TMAH (tetramethylammonium hydroxide). Selected elements were analysed with the help of ICP-OES. This diploma thesis builds on the bachelor thesis, which deals with the same problem. Final concentrations were compared with certified values of skimmed powdered milk. Data showed that the most accurate are methods of preparation of wet microwave ashing and destruction of matrix with TMAH. By using these methods, the effect of the dairy matrix that caused problems in the analysis, was largely eliminated. The diluted samples with and without Triton X-100 showed a bigger anomaly of measuring than the mineralization of wet ashing which came to the loss of analyte because of fat elements contained in milk.
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Determination of selected parameters in special types of beers brewed in the Czech Republic
Fähnrichová, Nikola ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with analysis of special types of beer brewed in the Czech Republic using three instrumental methods. Polyphenols were determined by high performance liquid chromatography. To determine organic acids was used ion exchange chromatography. Elementary analysis was performed by inductively coupled plasma optical emission spectrometry. The theoretical part of the work describes technology of beer production, chemical composition of beer, especially groups of substances which were analysed in this thesis. Principle of used methods is also described. The practical part of the work deals with preparation of tested samples, calibration samples and process analysis. The obtained results of analysed substances are summarized in the tables, discussed and compared with results of analysis of other authors. For the analysis it was used eighteen different types of special beer produced in the Czech Republic.
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Analysis of selected elements in milk by ICP-OES
Sekaninová, Renáta ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This Master's thesis is dealing with elementary analysis of milk. Theoretical part describes general characteristics, terminology with basic legislature and classification of milk. Large part is focused on chemical composition, especially on description of mineral substances selected for analysis in experimental part of this thesis. Choices of elementary analysis and preparation of samples for ICP-OES method conducted by other authors are also mentioned. Specification of emission spectrometry with inductively coupled plasma is crucial, a technique used for purposes of this dissertation. Experimental part deals with preparation of samples, approach of analysis and processing of measured results. The aim of this part is to compare concentration of analyzed elements in different kinds of milk. Samples from 15 different kinds of milk were used for analysis, which were determined by ICP-OES method. Results were compared to each other in discussion as well as with results from other authors.
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Analysis of milk by ICP-OES technique
Kaňová, Veronika ; Hrstka, Miroslav (referee) ; Diviš, Pavel (advisor)
The theoretical part of the thesis deals with the chemical composition of cow’s milk, with the description of chosen methods of sample pretreatment and with the description of the used technique ICP-OES. The practical part is aimed at individual preparations of samples and at analysis of chosen chemical elements (Ca, Na, K, Mg a P). Milk is a really complicated polydisperse system. The preparation of samples with milk is very important step before the measurement itself. In the thesis a comparison of four selected methods of sample preparation was made: bare dilution, dilution with addition of Triton X 100, wet ashing and sonication. Selected elements were analysed with the help of ICP-OES. Final concentrations were compared with CRM of dried milk. Data showed that the most accurate are methods of preparation of diluted sample and wet ashing. Four different types of milk were analysed with the help of those two selected methods. The diluted samples showed a bigger anomaly of measuring than the mineralization of wet ashing which came to the loss of analyte because of fat elements contained in milk.
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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.
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Influence of the chicken breeding method on the selected chemical constituents of chicken eggs
Michalec, Adam ; Vespalcová, Milena (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis is focused on the analysis of egg yolks and egg whites from chickens raised with different breeding methods in the Czech Republic using three analytical methods. The Kjeldahl method was used to determine the proteins, the Soxhlet method was used to determine the lipids and ICP-OES was used for elemental analysis. The theoretical part describes the history of chicken breeding, marking and distribution of eggs and composition of eggs based on various aspects. The main point was the separation of egg yolk and egg white and the subsequent description on the chemical and physiological level. Principle of used methods is also described. The experimental part deals with the preparation of samples, calibration samples and process analysis. All the results of analysed substances are summarized, statistically evaluated and compared with the other literature. For this analysis were used eleven different types of eggs from the Czech Republic from six different categories.
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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.
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