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Utilization of Catalytic Hydrogen Evolution in Electrochemical Analysis of Nucleic Acids
Fojta, Miroslav ; Daňhel, Aleš ; Špaček, Jan ; Havran, Luděk ; Šebest, Peter ; Orság, Petr ; Pivoňková, Hana ; Vosáhlová, J. ; Schwarzová-Pecková, K.
Catalysis of hydrogen evolution (CHE) at mercury in the presence of proteins was discoverd shortly after the introduction of polarography. In contrast, unmodified nucleic acids have not been reported to produce distinct signals due to the CHE to date. Chemically modified nucleic acids bearing certain extrinsic groups produce analytically useful signals due to hydrogen evloution catalyzed by the respective modifications. These species include (a) transition metal complexes, and (b) non-metal catalytically active organic moieties. In addition, the CHE has been reported to be invoved in guanine reduction process at the mercury-based electrodes.
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Determination of mercury content in selected samples important for health condition of population
VELÍŠKOVÁ, Romana
The subject of this bachelor work is the determination of content of mercury in selected samples, which are important for population´s health. Mercury and its compounds are among the most toxic materials in our environment. They occur in soil, air and also in food. Their toxicity depends on the form they are found in. Theoretical part of this work deals with basic information about mercury and its presence in the environment and also in different natural cycles and in industry and its effects on human health. The aim of this work is to assess the level of mercury contamination in selected samples. In the practical section of this work 14 samples of different materials are chosen and evaluated. The samples were taken from fish and related fish food products. Another samples are from soil around the train station, heat plant and crematory. Remaining set of samples are from various kinds of fuel and ecofuel and the last sample is from represented by the controversial dental amalgam. The analysis was performed by specialized absorbtion spectrometer AMA 254. Description of the samples extraction, elaboration and samples preservation are also added. The practical section of this work also includes analysis, principles of methods used and description of process of the mercury content. The results were statistically processed, noted and evaluated according to the currently valid legislation.
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Use of Silver Solid Amalgam Electrode for Determination of Acaricide Amitraz
Nováková, Kateřina ; Harvila, M. ; Navrátil, Tomáš ; Zima, J.
The electrochemical behavior of amitraz was studied at polished (p-AgSAE) and mercury meniscus modified (m-AgSAE) silver solid amalgam electrodes. The reaction mechanism was investigated using direct current voltammetry (DCV) and elimination voltammetry with linear scan (EVLS). The optimum conditions for differential pulse adsorption stripping voltammetry (DPAdSV) determination of amitraz were found in Britton-Robinson (BR) buffer mixed with ethanol in a volume ration of 1:4. DPAdSV with optimized parameters was applied for determination of amitraz in analyzed solutions. The limits of detection were calculated as 8.9 nmol L-1 (tacc = 20 s) for m-AgSAE and 0.168 mol L-1 (tacc = 20 s) for p-AgSAE. The proposed method was successfully applied for determination of this compound in real sample solutions.
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