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Voltammetric Determination of Flutamide at Screen-Printed Carbon Electrodes
Škvarla, Juraj ; Vyskočil, Vlastimil (advisor) ; Fischer, Jan (referee)
The paper deals with the electrochemical behaviour of flutamide at screen-printed carbon electrodes (SPCE) with the aim of optimizing conditions for their practical use in the in situ analyses. A stability of stock solution was verified and confirmed primarily. Then, an influence of pH, stirring time and flutamide concentration in the analyzed solution on the voltammetric behavior of flutamide were systematically studied using DC voltammetry and differential pulse voltammetry at SPCE. One well-developed voltammetric peak of flutamide was detected in the whole pH region investigated. The time of stirring appears to be of crucial importance for the result of measurements at all pHs. The longer time of stirring of the solution prior to measurements, the higher is the flutamide peak. Therefore, the time of stirring was set constant for the rest of measurements. The optimum conditions for voltammetric determination have been found in Britton-Robinson buffer pH 7.0 - methanol (9:1) for both DCV and DPV at SPCE. Concentration dependences were found to be linear for the range 1·10-6 - 1·10-4 mol·dm-3 and evaluable (but not reliable) up to 1·10-7 mol·dm-3 . Reached limits of quantification were 6·10-7 mol·dm-3 for DCV at SPCE and 8·10-7 mol·dm-3 for DPV at SPCE. The determination of flutamide in...
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Voltammetric Detection of Purine Nucleobases on Screen-Printed Graphite Electrodes Modified by Nanocarbon Materials
Hasoň, Stanislav ; Ostatná, Veronika ; Fojta, Miroslav
Recent studies have shown that the electrochemical oxidation of purine nucleobases (adenine and geaoine) at graphite electrodes is strongly dependent on the orientation of graphene sheets. their size and mutual distribution on the electrode surface. Edges and defects of graphene sheets affect the kinetics of oxidation processes, basal planes support the adsorption processes The aim of this study is to determine how model carbon nanomaterials including graphene, single-walled or multi-wailed carbon nanotubes. carbon nanofibres and mesoporous graphene affect the electrochemical oxidation or purine nuclebases on screen-printed carbon electrodes modified by these nanostructures in solution without and in the presence of copper.
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Voltammetric Determination of Flutamide at Screen-Printed Carbon Electrodes
Škvarla, Juraj ; Fischer, Jan (referee) ; Vyskočil, Vlastimil (advisor)
The paper deals with the electrochemical behaviour of flutamide at screen-printed carbon electrodes (SPCE) with the aim of optimizing conditions for their practical use in the in situ analyses. A stability of stock solution was verified and confirmed primarily. Then, an influence of pH, stirring time and flutamide concentration in the analyzed solution on the voltammetric behavior of flutamide were systematically studied using DC voltammetry and differential pulse voltammetry at SPCE. One well-developed voltammetric peak of flutamide was detected in the whole pH region investigated. The time of stirring appears to be of crucial importance for the result of measurements at all pHs. The longer time of stirring of the solution prior to measurements, the higher is the flutamide peak. Therefore, the time of stirring was set constant for the rest of measurements. The optimum conditions for voltammetric determination have been found in Britton-Robinson buffer pH 7.0 - methanol (9:1) for both DCV and DPV at SPCE. Concentration dependences were found to be linear for the range 1·10-6 - 1·10-4 mol·dm-3 and evaluable (but not reliable) up to 1·10-7 mol·dm-3 . Reached limits of quantification were 6·10-7 mol·dm-3 for DCV at SPCE and 8·10-7 mol·dm-3 for DPV at SPCE. The determination of flutamide in...
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Electrochemical Methods for Determination of Three Tumor Biomarkers for Neuroblastoma: Homovanillic Acid, Vanillylmandelic Acid, and 5-Hydroxyindoleacetic Acid
Makrlíková, A. ; Ktena, A. ; Fischer, J. ; Navrátil, Tomáš ; Vyskočil, V.
Tumor biomarkers – homovanillic acid, vanillylmandelic acid, and 5-hydroxyindoleacetic acid – have been determined at a screen-printed carbon electrode in small volume samples. For all measurements, Britton-Robinson buffer (0.04 moll−1, pH 3.0) was used as an optimum medium for all three analytes. Dependences of the peak current on the concentration were linear for all compounds, with the limits of quantification 0.8 μmol∙l–1 for homovanillic acid, 0.2 μmol∙l–1 for vanillylmandelic acid, and 0.2 μmol∙l–1 for 5-hydroxyindoleacetic acid. Depending on the results of the measurements, the future experiments should be performed in human urine.
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Voltammetric determination of anticancer drug flutamide at screen-printed carbon electrodes
Vyskočil, V. ; Navrátil, Tomáš ; Barek, J.
Flutamide, 4-nitro-3-trifluoromethyl-isobutylanilide, is the active component of a synthetic nonsteroidal antiandrogen drug, which is commonly used in the treatment of advanced prostate cancer. In this contribution, optimum conditions have been found vor voltammetric determination of flutamide by DC voltammetry (DCV) and differential pulse voltammetry (DPV) at screen-printed carbon electrodes (SPCEs). Under optimum conditions (Britton-Robinson buffer pH 7.0 - methanol (9:1)), linear calibration curves were measure with limits of quantification 6x10(-7) molL(-1) and 8x10(-7) molL(-1) for DCV at SPCEs, respectively. The newly developed methods were successfully applied to the determination of the drug in pharmaceutical formulation Apo-Flutamide (Eulexin tablets).
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