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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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Searching for Electrochemical Reduction Mechanism of Azidophenyl DNA Labels
Daňhel, Aleš ; Trošanová, Zuzana ; Balintová, Jana ; Hocek, Michal ; Fojta, Miroslav
This contribution brings new information to sporadic scientific results concerned to electrochemical reduction of aromatic azides. Selected compounds used as perspective DNA labels or their structural constituents such as, 4-azidophenyltrifluoroboronic acid, 4-azidophenyl modified deoxycytidine and next probable analogous compounds and/or products of their reduction, were voltammetrically studied and compared to each other in order to reveal a mechanism of their electrochemical reduction at mercury electrodes in aqueous media. Preliminary results obtained by cyclic voltammetry at mercury and carbon based electrodes and by mass spectrometry of the products isolated from batch electrolysis on mercury pool by preparative chromatography are discussed.
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