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Digestion methods for speciation analysis of toxicologically important forms of arsenic in tissue by hydride generation with cryotrapping and atomic absorption spectrometry
Taurková, Petra ; Rychlovský, Petr (advisor) ; Spěváčková, Věra (referee)
This diploma thesis develops methodology of arsenic speciation analysis by selective hydride generation with cryotrapping and atomic absorption spectrometry. Using this technique it is possible to determine toxicologically important forms of arsenic, i.e arsenites, arsenates and their mono-, di-, and trimethylated forms at concentration levels below 0,1 ng.ml-1 . The first part of the thesis is focused on testing tubular membrane gas dryers with nafion membrane for drying gaseous phase containing generated hydrides. The suitability for arsenic speciation analysis was investigated and transport losses of individual arsenic species were found. The second part describes mild digestion procedures suitable for arsenic speciation analysis in tissues. Two procedures were compared, acid digestion in phosphoric acid and more recent alkalic digestion by tetramethylammonium hydroxide. Digestion procedures were tested on certified reference material DOLT - 4 (Dogfish Liver) and chicken liver matrix. Key words: Tubular nafion membrane dryers, Arsenic speciation analysis, Digestion, Phosphoric acid, Tetramethylammonium hydroxide, Chicken liver, CRM DOLT - 4, Hydride generation, Atomic absorption spectrometry
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Novel Approaches to the Application of Electrochemical Volatile Compounds Generation in Spectrometric Methods
Červený, Václav ; Rychlovský, Petr (advisor) ; Spěváčková, Věra (referee) ; Komárek, Josef (referee)
Various possibilities for the use of electrochemical generation of volatile compounds for the determination of trace and ultratrace quantities of elements using atomic absorption spectrometry and optical emission spectrometry, respectively, were studied in this work. The Thesis is divided into four thematic sections. Electrochemical cold mercury vapor generation is common to the first two parts. The third part is devoted to electrochemical generation of the volatile form of cadmium and the last part deals with the use of the electrochemical hydride generator as a derivatization unit for speciation analysis of arsenic compounds. The optimization of each individual determination was carried out including, for example, various designs of the generator of volatile compounds (forms) of the analyte, the changes in the design of the gas-liquid separator, optimization of the concentration and the flow rate of all the solutions and the carrier gas. However, the value of the electric current employed was the most important parameter. In the first section, the in-situ trapping system of the cold mercury vapor generated in the graphite furnace (with the inner surface covered with a gold foil) of the atomic absorption spectrometer was also designed and optimized. The absolute limit of detection, 80 pg, was...
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Study of levels of selected toxic and benefit trace elements in human organism
Batáriová, Andrea ; Černá, Milena (advisor) ; Rychlovský, Petr (referee) ; Bencko, Vladimír (referee)
The work is focused on the study of variability in concentration and determination of reference values of selected toxic trace elements and benefitních in the human organism, which are monitored within the CZ-HBM (cadmium, lead, mercury, copper, selenium and zinc). The results shown here are based on concentrations of selected trace elements in blood and urine of adults and children from the locality Benešov, Plzen, Ústí nad Labem and Ždár nad Sázavou for the period 1996 - 2003. These data were processed by descriptive statistics annually. The aim was to undergo a detailed statistical analysis, taking account of indications of donors and children received a questionnaire (age, gender, location, smoking), to assess the development of long-term time series and to establish reference values valid for population groups in the period of time.
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