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Influence of interfering elements on the electrochemical selenium hydride generation
Vošmiková, Anna ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
This work is focused on the influence study of selected hydride forming elements (As, Sb), transition metals (Ni, Cu, Zn), anions (Cl- ,NO3 - ,SO4 - ) and cations (Ca2+ ,Na+ ), on the electrochemical hydride generation of selenium hydride. The analyte was converted to the volatile form and consequently atomized in a quartz tube atomizer. Atomic absorption spectrometer was used as a detection technique. For comparison, the same interference study was used to investigate for chemical hydride generation. The biggest influence on the analytical signal suppression was observed for other hydride forming elements at higher concentration (from 1mg/L of interfering elements the signal was suppressed by nearly 100 %). The transitions elements nickel and copper suppressed the analyte signal significantly. Neither selected anions nor cations suppress the signal significantly. No effect on the analytical signal was observed whet the sodium and calcium were tested at different concentration.
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Tubular electrolytic cell for electrochemical generation of volatile compounds
Luštincová, Petra ; Hraníček, Jakub (advisor) ; Červený, Václav (referee)
The newly constructed tubular flow-through electrolytic cell useful for electrochemical generation of volatile compounds was used in this presented work. The general aim of this work was to test several cathode materials to obtain the best basic characteristics of selenium determination by electrochemical hydride generation using the tubular electrolytic cell. The tested cathode materials were lead wire, lead/tin alloy (75 % of Pb and 25 % of Sn) and granulated lead. At first the optimizations of relevant working parameters were carrier out for all of these cathode materials. Under the optimal working parameters, the basic characteristics of selenium determination were found. The highest sensitivity (7.6 · 103 dm3 µg-1 ) and the lowest limit of detection (0.42 µg.dm-3 ) were obtained for granulated lead as cathode material. Subject words: Analytical chemistry Key words: Atomic absorption spectrometry, electrochemical generation of volatile hydrides, tubular electrolytic cell
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