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Thick-film sensors for electrochemical detection of species in aqueous solutions
Martynek, Daniel ; Adámek, Martin (referee) ; Prášek, Jan (advisor)
This work deals with the theory, principles and characteristics of electrochemical sensors, thick-film technology and electrodes used in electrochemistry. Methods for the detection of substances matters in solutions are discussed here. Main emphasis is given to differential pulse voltammetry and the influence of the method setup parameters to the measurement results. Experimentally, the work deals with the modification of thick-film working electrode with carbon nanotubes and subsequent activation of the electrode by nitric acid to increase the detection limit and the current response to selected heavy metals ions. Finally, the obtained results are compared with special commercial paste and discussed with the data state in literature.
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Voltammetric Determination of 2,4-Dichlorophenoxyacetic Acid and 2,4-Dichlorophenol on a Screen-Printed Carbon Electrode
Jančová, Jana ; Vyskočil, Vlastimil (advisor) ; Fischer, Jan (referee)
The aim of the presented Master Thesis was to study an electrochemical behaviour of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) resulting in the founding of optimum conditions for their voltammetric determination at a screen-printed carbon electrode (SPCE) using DC voltammetry (DCV) and differential pulse voltammetry (DPV). Voltammetric behaviour of both compounds was investigated in dependence on the pH of the medium (realized using Britton-Robinson buffer). The optimum pH for the voltammetric determination of 2,4-D on the SPCE was chosen to be pH 5,0 for both voltammetric techniques, and, for 2,4-DCP, it was chosen to be pH 6,0 for both voltammetric techniques. The determination of 2,4-D at a concentration of 1·10-4 μmol·L-1 showed good repeatability for both voltammetric techniques used (1.3% for DCV and 0.7% for DPV), and, for 2,4-DCP, it showed acceptable repeatability for both voltammetric techniques used (1.3% for DCV and 4.8% DPV). Under optimum conditions, the calibration dependence of 2,4-D was measured for DCV in the concentration range of 10-100 μmol·L-1 , with limit of quantification (LOQ) of 1.0 μmol·L-1 and limit of detection (LOD) 0.3 μmol·L-1 . Under optimum conditions, the calibration dependence of 2,4-D was measured for DPV in the concentration range...
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Thick-film sensors for electrochemical detection of species in aqueous solutions
Martynek, Daniel ; Adámek, Martin (referee) ; Prášek, Jan (advisor)
This work deals with the theory, principles and characteristics of electrochemical sensors, thick-film technology and electrodes used in electrochemistry. Methods for the detection of substances matters in solutions are discussed here. Main emphasis is given to differential pulse voltammetry and the influence of the method setup parameters to the measurement results. Experimentally, the work deals with the modification of thick-film working electrode with carbon nanotubes and subsequent activation of the electrode by nitric acid to increase the detection limit and the current response to selected heavy metals ions. Finally, the obtained results are compared with special commercial paste and discussed with the data state in literature.
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