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Study of the migration of selected metals from beverages packaging
Šťávová, Elena ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This master’s thesis follows on bachelor’s thesis and deals with study of migration of aluminium and tin from metal containers. Manufactory of metal containers, corrosion of cans, chemical behaviour of aluminium and tin in food, its effects on health and possibilities of the determination in food and characterization of inductively coupled plasma optical emission spectrometry (ICP-OES) are described in theoretical part. In experimental part 30 different beverages in cans and glass and 6 tomato purees purchased at common stores were analysed. Measured concentrations of aluminium in beverages from cans and from glass containers were compared. It was found that beverages from cans didn’t contain higher concentrations of aluminium than beverages from glass containers. This could be caused by the fact that the aluminium is very stable metal, it has high corrosive endurance and therefore is very suitable for food packaging. Measured concentrations of tin in tomato purees were compared with the maximum permissible level of tin in canned food determined by European legislation. None of them exceed the 200 mg/kg level. All of the measured concentrations were very low, because all of the cans contained protective layer of lacquer, which gives protection against corrosion and also effectively protects from releasing of tin into the can content.
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Preconcentration Techniques for Determination of Uranium Using the Modified Sorbents.
Moos, Martin ; Řehůřková, Irena (referee) ; Kanický, Viktor (referee) ; Kráčmar, Stanislav (referee) ; Sommer, Lumír (advisor)
The work has been focused on the preconcentration techniques for determination of uranium on the modified sorbent, with the final use of ICP-OES and ICP-MS. First ICP-OES at a wavelength of 385.958 nm was used for determination of uranium. Parameters were optimized and the effect of mineral acids (HCl, HNO3), tensides (Septonex, Ajatin) and organic reagents like (4-(2-pyridylazo)resorcinol, ammonium pyrrolidinedithiocarbamate, 8-hydroxyquinoline-5-sulphonic acid and 1,2-dihydroxyanthraquinone-3-sulphonic acid) was observed. For ICP-MS an isotope 238U was chosen. As an internal standard 209Bi (200 ?g•l-1) was used. Modified silica gel was used (Silicagel tethered with C18, C8 alkyls and phenyl) and two types of Amberlite XAD 4 and XAD 16 for the preconcentration of uranium (VI). Commercially produced Amberlite was modified as follows: Drying at 100 °C (24 hours), milled, minced sorbent was selected and fractionated to particles size ranging from 0.32 to 0.63 ?m and finally activated in methanol. The deionised water and Septonex (5•10-3 mol•l-1) at pH 8 were used for Amberlite conditioning. The optimal sorption of uranium (VI) proceeded at pH 8 in the presence of 4-(2-pyridylazo)resorcinol or ammonium pyrrolidinedithiocarbamate with Amberlite XAD-16 moreover with 1,2-dihydroxyanthraquinone-3-sulphonic acid. All organic reagents have mass concentration five time larger than uranium . For the elution of uranium the mixture of 1 mol•l-1 HNO3 with acetone (ratio of 1:1) was used. Acetone was evaporated and the final analysis performed using ICP-OES. The preconcentration of uranium (VI) using Silicagel-C18 conditioning was performed with ethanol, deionised water and Zephyraminu (5•10-4 mol•l-1) at pH 8. For the Silica-C8 and Silicagel-Phenyl the same conditioning procedure without zephyramin was used. Silica-C18 had the highest sorption efficiency with 1,2-dihydroxyanthraquinone-3-sulphonic acid, Silicagel-C8 with ammonium pyrrolidinedithiocarbamate and Silicagel-Phenyl with 8-hydroxyquinoline-5-sulfonic acid, all organic reagents have mass concentration five time larger than uranium concentration. As an optimal elution mixture acetone and ethanol (ratio of 1:1) in the presence of 1 mol•l-1 HCl was evaluated. Acetone and ethanol was evaporated and the final analysis was performed using ICP-MS. Silicagel-C18 was evaluate as the most effective in the presence of zephyramin and 1,2-dihydroxyanthraquinone-3-sulphonic acid. Sorption was also tested in the presence of 20 ?g•l-1 microelements (Be, V, Co, Ni, Y, Pb, Th, Cd) and in the presence of a defined concentrations of K, Na, Ca, Mg, Al and Fe. Direct analysis of uranium was carried out on samples of water from the river Ploucnice and Turonian aquifers containing uranium, 3,5 and 19,3 ?g•l-1. Different type of water required preconcentration of uranium (VI) on Silica-C18 in the presence of 1,2-dihydroxyanthraquinone-3-sulphonic acid and zephyramin. The analysis results gave statistically satisfactory results, which were confirmed using standard addition of 20 ?g•l-1.
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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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Monitoring of the tin release to the canned fruit from the used packaging
Flajs, Roman ; Vránová, Dana (referee) ; Diviš, Pavel (advisor)
This master’s thesis deals with the issue of the release of tin in canned fruit of used packaging. The theoretical part of the thesis is described canning fruit as raw material, its composition, methods of preservation, basic technological operations fruit processing, manufacture of compote, manufacture of metal packaging, marches corrosive metal packaging, chemical behavior of tin in foods and toxicity, methods for the determination of tin in foods with a focus on optical emission spectrometry with inductively coupled plasma. I the experimental part of the thesis was first ICP-OES optimized before to analysis of the 20 different samples compote purchased in chain stores. Tin concentration was determined by a fixed proportion compote. Measured concentration of tin were compared with the maximum permissible value in canned foods, which is allowed by European legislation. The tin content in all analyzed compote did not exceed the legislative limit of 200 mg/kg. The highest concentration of tin has been measured in sample conserved apricots namely 88,6 ± 2,8 mg/kg.
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Determination of micro and macro elements in bottled water by ICP-OES technique
Herman, Vít ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This Master’s thesis deals with the determination of selected micro and macro elements in bottled water purchased in retail chains Czech Republic. There are described macro elements and micro elements that occur in the waters, bottled waters legislation and the most frequent used instrumental methods for elemental analysis. In this work for the analysis of bottled water were used methods optical emission spectrometry with inductively coupled plasma (ICP-OES) and ion chromatography (IC). Elemental composition of bottled water after analysis corresponded to the composition indicated on the labels, there were recorded only minor deviations from the reported concentrations. All bottled water meets the conditions of the legislation of the Czech Republic. The measured data were statistically processed in the XL Stat program and by multivariate data analysis was examined whether it is possible to individual bottled water from each other based on the analyzes differentiate, which can help in verifying the authenticity of bottled water and in the detection of adulteration of bottled water for profit.
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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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Elemental analysis of different kinds of small fruit
Štursa, Václav ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the elemental analysis of soft fruit species such as currants and gooseberries. The theoretical part contains botanical description of both species, then description of nutritional properties of the individual analyzed elements and ends with a list of analytical methods suitable for elemental analysis in the food science and with a description of preparation. The experimental part deals with sample preparation and its analysis afterwards with spectroscopic techniques. Samples of different varieties of gooseberries, black, red and white currant from “Výzkumný a šlechtitelský ústav ovocnářský v Holovousích, s.r.o.” have been used for the analysis. Samples were mineralized in concentrated HNO3 and analyzed by ICP-OES technique. Difference in resultant concentrations of the analyzed elements (Ca, Cu, Fe, K, Mg, Mn, Na, P, Zn) between individual varieties were statistically compared by Tukey’s multiple comparison method and results achieved have been as well compared with the results reported in available literature.
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Determination of tin in canned fruits
Šťávová, Elena ; Hrstka, Miroslav (referee) ; Diviš, Pavel (advisor)
This bachelor’s thesis deals with determination of tin in canned fruits. Fruit processing, manufactory of compotes, manufactory of metal packaging products, corrosion of cans, chemical behaviour of tin in food, its potential toxicity, possibilities for the determination of tin in food and characterization of inductively coupled plasma optical emission spectrometry are described in theoretical part. In experimental part, ICP-OES technique was firstly optimized and then 28 different compotes purchased at common stores were analysed. The concentration of tin was determined only in fruit juice due to the easier sample preparation, even though quantity of tin in the solid part and in the juice can differ. However, the difference is not too big. Measured concentrations of tin were compared with the maximum permissible level of tin in canned food determined by European legislation. None of them exceed the 200 mg/kg level. When processing the results, it was found that the coating of the can has a significant influence on the content of tin in canned fruits. Concentrations of tin in laquered cans were significantly lower than in unlaquered cans.
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Elemental analysis of different currants varieties
Kovaříková, Tereza ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with the elemental analysis of different varieties of red (Ribes rubrum), white (Ribes vulgare) and black currant (Ribes nigrum). The theoretical part contains botanical description of each variety of this small fruit, then description of analyzed elements and their function in human metabolism. Then there are described analytical methods suitable for elemental analysis in food. The experimental part is focused on the preparation of sample and its subsequent analysis by spectroscopic teqniques. All of the currant samples were given by Research and breeding institute of pomology Holovousy L.td. All the samples were mineralized by the wet ashing in concentrated HNO3 and analyzed by the ICP–OES teqnique. Final concentrations of each elements (Na, K, Ca, Mg, P, Fe, Zn, Cu, Mn) were stastistically compared by Tukey’s multiple comparation method and then have been compared with the results reported in literature.
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Elemental analysis of the different gooseberries varieties
Nývltová, Barbora ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This bachelor thesis describes and explores the elemental analysis of several new varieties of red and green gooseberries. The theoretical part deals with the history, taxonomy, cultivation and biological characteristics of gooseberry. The next part of the thesis is focus on the summary of nutritional parameters of the analyzed elements and it also describes the methods which characterize the analysis in the food use. The experimental part deals with the preparation of the sample, its subsequent decomposition by using wet way and of the actual analysis using the technique ICP-OES. The sample was provided by “Výzkumný a šlechtitelský ústav ovocnářský v Holovousích, s.r.o.”. The results of analyzed elements (Cu, Fe, Mg, Mn, P, Zn, Ca, K, Na) in the various varieties of gooseberry were further evaluated using statistical methods. These results were then compared with the available databases. The most promising in terms of the content of individual elements proved to be a variety of red gooseberry Rolonda and Jocheline, a variety of green gooseberry Invicta and Mucurines.
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