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Testing of the possible applications of the flow-through dual amperometric detector
Vikartovský, Andrej ; Dejmková, Hana (advisor) ; Baluchová, Simona (referee)
In this work, the possibilities of using an electrochemical dual detector in a flow arrangement were investigated using flow injection analysis. The dual detector was first tested for potassium ferrocyanide for its reversible oxidation at the generation electrode and subsequent reduction at the detection electrode. The possibilities of determination of nitro substances were explored, when hydroxylamine was formed by the reduction of nitro groups on the generation electrode, which was subsequently oxidized on the detection electrode. Thanks to determination in the oxidation potentials, it was possible to avoid the noise caused by oxygen reduction and the detection limit for dinitrophenol 0.47 μmol∙dm−3 was achieved. The possibilities of using a dual detector for detection in reduction potentials by minimizing the influence of oxygen, by reducing it on the generation electrode, were verified. Furthermore, the possibility of using a dual detector for the determination of dopamine in the presence of ascorbic acid based on the reversible oxidation of dopamine and the irreversible oxidation of ascorbic acid was investigated. The limits of dopamine detection using reduction on the detection electrode were 0.31 μmol∙dm−3 in the presence of ascorbic acid with a concentration of 0.1 mmol∙dm−3 . In the...
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Electrochemical detection of trace amounts of nitrated explosives
Barek, J. ; Fischer, J. ; Vyskočil, V. ; Pecková, K. ; Navrátil, Tomáš ; Josypčuk, Bohdan
Nitrated organic compounds belong to the group of the most frequently used explosives. Detection of low levels of such compounds is very attractive in these days. Due to the easy reducibility of the nitro group, voltammetry seems to be very suitable method for these purposes. For these determinations the following electrodes were used: were used hanging mercury drop electrode, meniscus modified silver solid amalgam electrode, miniaturized paste silver amalgam electrode, paste electrode on the basis of silver amalgam powder and proper organic liquid were used.
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Voltametrické stanovení sloučenin dusíku pomocí stříbrné pevné amalgámové elektrody
Daňhel, A. ; Barek, J. ; Josypčuk, Bohdan ; Pecková, K.
Silver amalgam is a good electrode material for construction of new types of electrodes. In this work a silver solid amalgam paste electrode was prepared. The pastes were mixed from a silver solid amalgam powder and a mineral oil, silicone oil, paraffin oil and tricresylphosphate, stuffed into a Teflon body of electrode. The silver paste amalgam electrodes are expected to provide new possibilities for determinations of electrochemically reducible compounds by modern voltammetric methods. The main expected advantage is the possibility of easily renewable surface as in the case of carbon paste electrodes.
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