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Study of electrochemical behaviour of tauroursodeoxycholic acid at mercury-based electrodes
Pišnová, Kateřina ; Schwarzová, Karolina (advisor) ; Navrátil, Tomáš (referee)
This thesis deals with electrochemical behaviour of tauroursodeoxycholic acid (TUDCA) at silver solid amalgam electrode modified by mercury meniscus (m-AgSAE), polished silver solid amalgam electrode (p-AgSAE) and hanging mercury dropping electrode (HMDE). This thesis is a part of a bigger scientific research that deals with synthesis and characterization of supramolecular systems based on natural steroid compounds and its conjugates. TUDCA offers one reduction peak at m-AgSAE in the environment of Britton - Robinson buffer in range of pH 6.0 - 13.0. The potential of this peak is around −1200 mV. Using cyclic voltammetry was determined that the process on the electrode surface is quasireversible, the reduction is controlled by diffusion and the anodic process is controlled by adsorption. Concentration dependence measured at HMDE by direct current voltammetry in 0.04 mol∙l-1 borat buffer (pH 9.1) is linear in two concentration intervals - 1∙10-3 - 2∙10-4 mol∙l-1 and 1∙10-4 - 8∙10-6 mol∙l-1 of TUDCA. There was no linear dependence between the increase of concentration of TUDCA and the height of the peak obtained on amalgam electrodes by methods DC, DP, cyclic and "square-wave" voltammetry. On HMDE was in several short concentration intervals measured by a CV method a linear dependence of cathodic and...
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Study of electrochemical behaviour of tauroursodeoxycholic acid at mercury-based electrodes
Pišnová, Kateřina ; Schwarzová, Karolina (advisor) ; Navrátil, Tomáš (referee)
This thesis deals with electrochemical behaviour of tauroursodeoxycholic acid (TUDCA) at silver solid amalgam electrode modified by mercury meniscus (m-AgSAE), polished silver solid amalgam electrode (p-AgSAE) and hanging mercury dropping electrode (HMDE). This thesis is a part of a bigger scientific research that deals with synthesis and characterization of supramolecular systems based on natural steroid compounds and its conjugates. TUDCA offers one reduction peak at m-AgSAE in the environment of Britton - Robinson buffer in range of pH 6.0 - 13.0. The potential of this peak is around −1200 mV. Using cyclic voltammetry was determined that the process on the electrode surface is quasireversible, the reduction is controlled by diffusion and the anodic process is controlled by adsorption. Concentration dependence measured at HMDE by direct current voltammetry in 0.04 mol∙l-1 borat buffer (pH 9.1) is linear in two concentration intervals - 1∙10-3 - 2∙10-4 mol∙l-1 and 1∙10-4 - 8∙10-6 mol∙l-1 of TUDCA. There was no linear dependence between the increase of concentration of TUDCA and the height of the peak obtained on amalgam electrodes by methods DC, DP, cyclic and "square-wave" voltammetry. On HMDE was in several short concentration intervals measured by a CV method a linear dependence of cathodic and...
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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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