The aim of this master's thesis was to determine the contents of cadmium, lead and mercury in sea fish. Fresh and frozen fish from 17 FAO localities were bought in Czech markets. The theoretical part of this work describes the determined heavy metals and their relation to the environment. All 30 analyzed fish species are also described here. Atomic absorption spectrometry technique was used for determination of cadmium, lead and mercury concentration in the practical part of the work. Twelve samples exceeded the maximum levels for mercury (0.5 mg/kg or 1 mg/kg for selected fish species) and three fish samples exceeded the maximum level for cadmium (0.05 mg/kg) set by Commission Regulation (EU) No 1881/2006, as amended. The maximum level of lead concentration (0.3 mg/kg) was not exceeded in any fish sample. Results of this work show, that samples of marlin (Tetrapturus albidus) and swordfish (Xiphias gladius) are one of the most contaminated fish which can pose a great risk for human health after regular consumption. Because mercury and cadmium contents in some samples were higher than maximum levels recommended by World health organization WHO and Czech legislation, our research initiated an investigation of CAFIA, which led to withdraw some batches of the fish from the Czech markets.

The aim of this master’s thesis was to determine the total contents of selected nutrients (magnesium, copper, calcium, zinc and iron) in quail eggs during the time of their storage. The contents of elements were measured in fresh eggs and then after first, second, third, eighth, fifteenth, twenty – ninth, forty – third and fifty – seventh day of storage. Theoretical part is focused on the production and importance of eggs, their creation and chemical composition. Additionally, this part deals with the more detailed characteristics of aforementioned elements and with their relationship to human nutrition. The practical part includes the results of measured contents of elements in whole egg, yolk and egg white. The analysis was carried out using atomic absorption spectrometry. The results show that the time of storing has no effect on the contents of selected elements in quail eggs.

The aim of this master´s thesis was to determinate selected nutrients in hen eggs depending on the time of their storage. The content of nutrients in hen albumen, hen yolk and hen melange was measured in fresh eggs ang in storaged eggs after one, two, eight, fiveteen, twenty nine, forty three and fifty seven days. Teoretical part of thesis is focused on chemical composition of hen egg, breeding, history, storage and consumption. Another part of thesis deals with selected nutrients, specifically by magnesium, copper, calcium, zinc and iron. In practical part the results are presented. The content of these elements was determined with using atomic absorption spectometry. The results show that the storage time did not have an effect on the contents of the selected elements in the eggs. Formula clause:hen egg, magnesium, copper, calcium, iron, zinc, atomic absorption spectrometry

This Master thesis is a part of a project: Hydride atomizers for atomic absorption and atomic fluorescence spectrometry - new horizons (GA ČR, P206/17-04329S, principal investigator: prof. RNDr. Jiří Dědina, CSc. DSc.) of which the general target is to make a leap towards the ideal hydride atomizer by optimization of atomization based on the knowledge of the distribution of free atoms and hydrogen radicals inside the atomizers. This thesis contributes to the project by optimizing the atomization parameters for atomic absorption spectrometry with hydride generation. The atomization parameters were optimized for three different types of atomizers - multiatomizer, diffusion flame and "flame-in-gas-shield" atomizer using three different analytes - bismuth, lead and tin. Optimal atomization parameters were found for each of the atomizer and each of the analyte - carrier gas flow and flow of other gases if needed for the analysis. Calibration curves and analytical figures of merit such as sensitivity, LOD and LOQ were estimated. Final comparison is based on the data obtained from calibration curves. MDF and FIGS atomizers are mostly used with AFS detection and they provide lower sensitivity and higher detection limits with AAS detection in comparison with MMQTA. Since the analytes are known to trap...

This thesis deals with the development of a method suitable for determination Te(IV) by UV-photochemical generation of volatile compounds (UV-PVG) in liquid samples. Atomic absorption spectrometry (AAS) and atomic fluorescent spectrometry (AFS) were used as detection methods. The basis of the apparatus for UV-PVG was a mercury lamp wrapped by PTFE capillary. Firstly, the experimental parameters were optimized for both methods. The optimized parameters were the type, concentration, pH and flow rate of the reaction medium, the length of the PTFE reaction coil, carrier gas flow rate (argon), supportive gas flow rate (hydrogen) and atomization temperature. The figures of merit with both detection methods were determined and compared after the method was optimized. Detection limits achieved for these two detection methods were 6,0 µg dm-3 for AFS and 1,50 µg dm-3 for AAS. Performed interference study confirmed a significant effect of many cations of transition metals and hydride forming elements on tellurium determination. The influence of nitric acid in the sample was studied separately. The suitability of the method for tellurium determination was confirmed by using a spiked certified reference material.

The master thesis deals with comparison of atomic fluorescence spektrometry and high resolution continuum source atomic absorption spektrometry for three methods generation of volatile compounds Antimony. In both methods of atomic antimony detection, it compares the most common chemical generation of volatile compounds (hydrides) with two alternative methods - electrochemical and UV - photochemical. The values of performance parameters for the determination of Sb(III) and Sb(V) were determined for all the above combinations. In the case of chemical generation, a surprisingly almost four times higher limit of detection of Sb(III) was found in connection with AFS detection than AAS detection. The final part was devoted to UV - photochemical vapor generation, with AAS detection for Sb(III) reaching limit of detection 4,96 ppb, for Sb(V) 8,63 ppb. Although UV - photochemical generation of volatile antimony compounds did not reach such performance parameters as chemical or electrochemical generation, it was observed that the sensitivity of antimony determination increased greatly when introducing oxygen into the apparatus. The interference study also found a significant positive effect of Fe(II) on the generation efficiency, and this modification partially persisted without further introduction of these...

Contamination of soils with heavy metals is one of the serious environmental problems threatening human being. Heavy metals are considered as the special hazard of soil pollutants because of the adverse effects on the plant growth, the amount, activity of useful microorganisms in soils and the quality of food. Regard to the persistent and toxicity, the heavy metals are toxic when we consider different kinds of pollutants in soils. In the soil, zinc (Zn), cadmium (Cd), lead (Pb) and mercury (Hg) toxicities frequently occur than the other metals because of their precipitation and sorption by the soil. It is a very dangerous situation because when these metals are taken up by plants, they can be transported to the food web and food chains. In the present study, the accumulation of four heavy metals (mercury, zinc, lead and cadmium) in the whole grain of spring accessions of emmer, einkorn and common spring wheat cultivars and potato (Solanum tuberosum) is reported. Heavy and essential elements were monitored in potato cultivars in the exact field experiments and in hydroponically grown plants. The elements were determined by methods FAAS, ET AAS, and AMA (Advance Mercury Analysis). Statistical analyses were performed using SPSS 9.0 with the Tukey HSD (Honestly Significant Difference) test (alpha equal to 0.05). In our study, the concentration of heavy metals decreased in the order zinc (Zn) > lead (Pb) > cadmium (Cd) > mercury (Hg) in the wheat grain. The comparison between three varieties of investigated wheat revealed that the emmer wheat was rich in zinc content (62.12 mg kg-1 dry matter), while the spring wheat had the lowest average concentration of zinc in the grain (40.99 mg kg-1 dry matter). Generally, the values of lead concentration in grain wheat varieties were low (ranging from 0.1268 mg kg-1 dry matter to 0.2950 mg kg-1 dry matter). The concentrations of mercury in four typical growth stages of wheat (boot stage 10, heading stage 10.2 1/4 of head emerged, leaf-stage 10.2 and stage ripening 11 according to Feekes) were also determined. It has been shown that the concentrations of mercury in different wheat varieties were absorbed differently at different growth stages of plant. Stage 10.2 and leaf stage 10.2 showed the high mercury content (0.0152 mg kg-1 dry matter and 0.0214 mg kg-1 dry matter, respectively). Among individual varieties significant differences were determined. Amounts of toxic and potentially toxic elements detected in investigated potato tubers are characterized by a large variability within investigated groups. Performing statistical analysis (one way ANOVA) showed that there were no significant differences between two investigated groups of samples (samples from Uhříněves and Valečov in the year 2013 and 2014) considering either one of investigated metals. Measurable levels of mercury were found in smallest amounts in all investigated potato samples comparing to other metals (Cd, Pb). Plant cells compared to animal cells are characterized by the formation of cell walls. Plasma membrane or cell membrane is a biological active membrane separating the interior of cell from the outside environment. An adjusted method for isolation of protoplasts was developed and adapted for isolation of protoplasts from plant material (potatoes). In our experiment, the plants were grown hydroponically in the Research Institute of Plant Crops Prague-Ruzyně. If we examine the plant membrane, one option is to remove the cell wall by means of special mixture enzymes. Protoplasts were released in the dark at 25 degrees of Celsius for 18 hours. The 70 and 90 microns sieve was used to filter and then centrifugation for 5 minutes at 100 x g. All the steps were carefully carried out to prevent the damage or breakage of protoplasts.

Removal of lead from municipal wastewater using a constructed wetland with a horizontal subsurface flow was studied. Wastewater, wetland plant and sediment samples were analyzed using an AAS Thermo Scientific iCE 3500. Average concentrations of lead in inflow and outflow water in 2015 were 1.47 and 0.74 ?g/l, respectively. Average concentrations of lead in inflow and outflow water in 2016 were 0.75 and 0.38 ?g/l. The average efficiency of lead removal was 49.2 %. Lead concentrations in vegetation (Phragmites australis) varied in the range of 0.081-0.087 mg/kg and 0.48-0.17 mg/kg for the above and belowground biomass, respectively. Lead concentration in sediments were 9.79 and 4.86 mg/kg at distances of 1 and 10 m from inflow zone. Lead and other heavy metals were predominantly removed from wastewater at the initial part of the wetland bed.

Mercury and its compounds are one of the most toxic global pollutants in the environment. It occurs in all segments of the environment, and it attains the food chain ang human body by people consuming fish. The theoretical part of this thesis examines the characteristics of mercury, its occurrence, the roots of its pollution, and the toxicity of various forms of mercury. Consequently, the thesis delineates analytical methodologies applied to determine the overall level of mercury and chemical forms of mercury. The practical part focuses on monitoring the level of mercury and methylmercury in 12 extracts of fish meat. The analyzer AMA 254 has been used to determine the level of mercury and methylmercury in these extracts. Based on the level that resulted from the measurements, the thesis concludes a risk that correlates with consuming this type of meat.

Theoretical part of the master thesis deals with the occurrence of different mercury species in the environment and describes analytical methods used for determination of mercury in biological samples. In practical part of the master thesis mercury concentration in 14 samples of selected fish and fish product was determined using single purpose absorption spectrometer AMA 254. Measured results were statistically processed and consulted with EU legislative norm.