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Polarographic Determination of Genotoxic 2-Amino-9-fluorenone
Hájková, Andrea ; Vyskočil, Vlastimil (advisor) ; Dejmková, Hana (referee)
of Bachaleor Thesis The aim to this work was to find the optimum conditions for polarographic determination of genotoxic 2-amino-9-fluorenone (2-AFN) that can negatively affect the living and working environment. Foremost, the stability of 2-AFN stock solution in methanol was monitored using UV-VIS spectrophotometry and an optimal ratio of buffered aqueous and methanolic phase was found out for following polarographic measurements at a classical mercury dropping electrode (DME). The dependence of polarographic behavior of 2-AFN (of concentration 1×10-4 mol dm-3 ) on pH of analyzed solution was measured using DC tast polarography (DCTP) and differential pulse polarography (DPP) in the pH range 1.9 - 12.8, in the medium of Britton-Robinson (BR) buffer - methanol (9:1). The mechanism of polarographic reduction of electrochemically reducible oxo group at 2-AFN has been proposed on the basis of thus observed behavior. The optimum medium of BR buffer pH 4.0 - methanol (9:1) has been chosen for both polarographic techniques. The concentration range from 1×10-6 to 1×10-4 mol dm-3 was measured using DCTP at DME and from 1×10-7 to 1×10-4 mol dm-3 using DPP at DME. Reached limits of quantification (LQs) were 5×10-7 mol dm-3 and 1×10-7 mol dm-3 for DCTP at DME and DPP at DME, respectively. For comparison, the...
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The use of mercury electrodes to determine tauroursodeoxycholic acid
Pišnová, Kateřina ; Schwarzová, Karolina (advisor) ; Dejmková, Hana (referee)
This thesis is devoted to the study of reduction of Tauroursodeoxycholic acid (TUDCA) on mercury electrodes - on the hanging mercury drop electrode and a mercury electrode, using polarographic (difference pulse polarography (DPP), direct current tast polarography (DCTP)) and voltammetric (difference pulse voltammetry (DPV), adsorptive stripping differential pulse voltammetry (AdS-DPV)) techniques. TUDCA is a conjugate of ursodeoxycholic acid and taurine, which is used as medication. It was discovered that TUDCA gives a single peak (wave) and the potential of this peak (half-wave potential) is about -1200 mV. The most sensitive method used was DP voltammetry, which has limit od detection 3,17.10 6 mol.l 1 and limit of quantification 1,05.10 5 mol.l 1 , as it has a much lower limit of detection (2,96.10 7 mol.l 1 ) and limit of quantification (9,87.10 7 mol.l 1 ) than DP polarography. In applying AdS-DPV method the peak height was increased only by about 20 %, therefore this method was evaluated as analytically unbeneficial for this measurement. It was discovered that the methods used for the characterization of the electrode happening are controlled by adsorption and are quasi-reversible; probably is reduced proton of sulfonic group. Furthermore, it was discovered that TUDCA does not interfere with...
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Polarographic Determination of Genotoxic 2-Amino-9-fluorenone
Hájková, Andrea ; Dejmková, Hana (referee) ; Vyskočil, Vlastimil (advisor)
of Bachaleor Thesis The aim to this work was to find the optimum conditions for polarographic determination of genotoxic 2-amino-9-fluorenone (2-AFN) that can negatively affect the living and working environment. Foremost, the stability of 2-AFN stock solution in methanol was monitored using UV-VIS spectrophotometry and an optimal ratio of buffered aqueous and methanolic phase was found out for following polarographic measurements at a classical mercury dropping electrode (DME). The dependence of polarographic behavior of 2-AFN (of concentration 1×10-4 mol dm-3 ) on pH of analyzed solution was measured using DC tast polarography (DCTP) and differential pulse polarography (DPP) in the pH range 1.9 - 12.8, in the medium of Britton-Robinson (BR) buffer - methanol (9:1). The mechanism of polarographic reduction of electrochemically reducible oxo group at 2-AFN has been proposed on the basis of thus observed behavior. The optimum medium of BR buffer pH 4.0 - methanol (9:1) has been chosen for both polarographic techniques. The concentration range from 1×10-6 to 1×10-4 mol dm-3 was measured using DCTP at DME and from 1×10-7 to 1×10-4 mol dm-3 using DPP at DME. Reached limits of quantification (LQs) were 5×10-7 mol dm-3 and 1×10-7 mol dm-3 for DCTP at DME and DPP at DME, respectively. For comparison, the...
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