National Repository of Grey Literature 316 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Hair as a bioindicator of contamination of risk metals
Zmijová, Marie ; Řezáčová, Veronika (referee) ; Zlámalová Gargošová, Helena (advisor)
The use of hair as a bioindicator of environmental contamination by risk elements is becoming more and more common. This bachelor thesis deals with the use of this matrix for analysis using the voltammetric method. It focuses on the optimization of the method for determining the concentration of cadmium, copper, lead and zinc in real hair samples and monitors the effects on the incorporation of these elements into the hair fiber. The presence of zinc and copper was confirmed in all samples analyzed. Cadmium could only be quantified in one sample. The effect of gender and age on the concentration of elements has not been demonstrated. Concentration of lead has been linked to smoking, with higher concentrations found in smoker’s hair than in non-smoker’s.
Monitoring of selected metals in comercial bio wines
Bortlová, Alžběta ; Reichstädter, Marek (referee) ; Pořízka, Jaromír (advisor)
This bachelor thesis is focused on monitoring of selected metals in commercial organic wines. The aim of this thesis was to compare element content of organically produced wines with wines originating from other agrotechnical production system. Optical emission spectrometry with inductively coupled plasma (ICP-OES) was used for element analysis of wine. Statistical method analysis of variance has been used to assess whether the concentrations of the elements showed statistical differences between wines originating from organic production and wines originating from other production systems. Statistical differences were found in 3 of 20 analysed elements. Correlations between the element analysis and type of production system of grapevine were observed in content of the zinc, nickel and manganese.
The presence of pollutants in matrices of bioindicators
Vlček, Ladislav ; Vávrová, Milada (referee) ; Doležalová Weissmannová, Helena (advisor)
This master‘s thesis concerns with occurrence of heavy metals in the environment, mainly in the matrices of bioindicators. Special attention is given to occurrence of mercury in the environment and its quantification in bioindicators. Mercury and its compounds are today considered as one of the most significant contaminants in the environment. Some sorts of mushrooms cumulate sizable amounts of mercury in their fruiting body and therefore we can use them to consider loading of different areas. Eight areas in Vizovice and its surroundings were chosen for these purposes and during the years 2006 – 2008 harvested 50 samples from 19 sorts of mushrooms from there. The concentrations of Hg were determined in all samples by single-purpose absorption spectrometer AMA 254. Comparison of the mercury content between individual sorts of mushrooms in the same area as well as comparison of loading of areas was performed and also bioaccumulation ability of individual sorts of mushrooms was determined.
Polarographic analysis of water
Klečka, Tomáš ; Rozman, Jiří (referee) ; Čížek, Martin (advisor)
This bachelor's project creates the necessary theoretical foundation of polarography and voltametry in the first part, which is needed to successful measurement using these technics. In the second part there is realized measurement with anodic stripping voltametry and accomplished evaluation in MATLAB. Finally there is example of procedure for laboratory task with polarograph.
Use of pollution indices for evaluation of soil contamination
Čmelíková, Dorota ; Pavlovský, Jiří (referee) ; Doležalová Weissmannová, Helena (advisor)
This thesis focuses on heavy metal contamination of soil and the use of pollution indices for its evaluation. Two regions were selected for assessment and comparison. The chosen heavy metals were mercury, zinc, copper, lead and cadmium. These heavy metals were analysed in 15 samples from Kyjov nad 15 samples from Ostrava. Methods of analysis were AMA-254 and FAAS. The established concentrations were used to calculate pollution indices and for health risk assessment. Pollution in Kyjov was assessed as low to medium without any health risks. Ostrava region was assessed as moderately to highly polluted with a low health risk, especially for children.
Hydrogels of Humic Acids - Experimental Model and Application Form
Sedláček, Petr ; Klučáková, Martina (advisor)
The thesis deals with a utilization of hydrogels made of humic acids in both basic and applied research of this valuable natural material. The attention is paid to an interaction between the humic gel and cupric ions as the model heavy metal. The main experimental part focuses on an optimation of simple laboratory diffusion methods which serve as an innovative tool for modeling pollutants’ transport in natural humic environments. Various techniques were used in order to determine a diffusion coefficient of cupric ions in humic gel; the value is closely linked with the studied interaction between solid content of the gel and the diffusing species. Consequently, the diffusivity can be used as a standard parameter for basic reactivity mapping studies concerning humic substances. The final chapter of the thesis deals with a preparation of mixed reversible hydrogels formed by a reaction between humic acids and chitosan. These materials represent a suitable colloidal form for humic acids’ industrial and agricultural applications.
Thick-film sensors for heavy metals detection
Polický, Jiří ; Adámek, Martin (referee) ; Prášek, Jan (advisor)
This work covers an area of heavy metals detection using thick-film sensors. Fabrication of screen-printed thick-film sensor and electrochemical analytical methods for detection of chemical elements in aqueous solutions are described in this work. Several commercial and own prepared thick-film pastes were used for carbon based working electrodes. The electrochemical properties of the pastes were examined by cadmium ions detection in potassium chloride solution using differential pulse voltammetry. The best results were achieved on the electrode made of direct grown carbon nanotubes on the electrode layer NM22. A detection limit 20×10-6 mol l-1.was reached with this working electrode material during oxidation process.
Chromium and chromium species cycle in environment
Nevrlá, Jana ; Sommer, Lumír (referee) ; Dočekalová, Hana (advisor)
This work focuses in the first theoretical part mainly on the possibility of entering various forms of chromium into the environment, their accumulation and transformation in environmental compartments. There are also described methods of sampling for analytical determination of chromium, the type of treatment of these samples and the most analytical methodologies for the determination of chromium in the oxidation stage III and VI. The experimental part is focused on the quantitative determination of Cr(III) and Cr(VI) in waste water, taken from the neutralizatoin station of the Chemical faculty of Brno University of Technology, by using selected spectrophotometric methods and the obtained results are compared with the results of analytical determination of total chromium by atomic absorption spectrometry.
Analysis of thermal power plants environmental impacts using radioanalytical methods
Král, Dušan ; Ing. Ondřej Huml, Ph.D., KJR FJFI ČVUT v Praze (referee) ; Katovský, Karel (advisor)
Operation of classical power sources, like coal fueled thermal power plants, causes more or less strong impact on surrounded environment. Beside to the generally discussed CO2 emissions, there are CO, SOx, NOx too; and also fly ash emissions containing various trace elements depending on coal quality. Heavy trace elements carried by fly ash generate locally distributed fallout and contaminate soil in the power plant neighborhood for many years. These elements may be detected in soil samples as well as in biomass. Objectives of this work are to find and quantify trace elements in soil samples near Oslavany hard coal fueled thermal plant, which was in operation from 1913 to 1993. Power plant did not use any advanced fly ash filters. Hard coal was used as a fuel for power plant and it was mined locally in Rosice-Oslavany coal district in very deep mines (up to 1428 m). Coal contained a lot of trace elements. A mine as well as power plant is for more than 20 year closed, but trace elements can be still find in the environment. Main goal is to find these elements using activation analysis and gamma-ray spectrometry methodology. We have assembled thirty six soil samples in square lattice drawn around Oslavany power plant brownfield. On behalf of cooperation with colleagues from the Czech Technical University in Prague and their Open-Access project, we irradiated samples in three vertical channels of VR-1 research nuclear reactor. Irradiated samples were transported to gamma spectroscopy & activation analysis laboratory and measured by HPGe detector. Gamma spectra were analyzed and some trace elements identified. We have determine relative and absolute concentration of found elements. We observe and determine activity and weight of As, U, Ba, La, Eu, Mn, K, V, Mg and Na only. Results show a real suspicion for increase of trace elements in soil samples of hard coal power plant surroundings.
Analysis of substances potentially dangerous to humans found in lipsticks
Horáková, Kristýna ; Kučerová, Simona (referee) ; Diviš, Pavel (advisor)
The diploma thesis deals with the determination of the content of risk elements and parabens in lipsticks and the assessment of possible negative effects on human health associated with the use of lipsticks. Parabens were analyzed by high performance liquid chromatography with diode array detection (HPLC-DAD). Aluminum, cadmium and lead were analyzed on an inductively coupled plasma mass spectrometer (ICP-MS). The mercury content was determined using an atomic absorption spectrometer with an UV detector (AAS-UV). A total of 36 lipstick samples from 22 cosmetic brands were selected for analysis, with a savings price in the range of CZK 50–1500. Based on the measured metal concentrations, the hazard quotients (HQ) for individual metals as well as the total hazard index (HI) for the sum of all metals were calculated. Metal concentrations in lipsticks were further processed using Kruskall-Wallis Anova to divide samples according to price categories. The relationship between the content of individual metals and the purchase price has not been proven. Furthermore, a Kolmogór-Smirnov test was performed on these data to compare groups with vegan and not vegan composition. The content of aluminum, which was about 2.5 times lower in vegan cosmetics, proved to be statistically significant for this distribution. Parabens were detected in the minimum number of lipsticks examined, but in some cases information on the content of parabens was missing on the product packaging.

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