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Voltammetric determination of 4-aminopyridine
Kudláčková, Kateřina ; Zima, Jiří (advisor) ; Fischer, Jan (referee)
In this thesis, the voltammetric behavior of 4-aminopyridine was investigated using carbon paste electrode. Differential pulse voltammetry was used for the study. Measurements were carried out in Britton-Robinson butter medium with different pH values. Optimal pH value found was 9. The electrode passivation during consecutive measurements of 4-aminopyridine without the surface renewal was confirmed, while the accumulation time had no influence on peak heights of 4-aminopyridine. Limit of detection was 8,76×10-6 mol dm-3 and limit of quantification was 1,85×10-5 mol dm-3 of 4-aminopyridne under optimal conditions. The linearity of the calibration curve was evaluated using the correlation coefficient.
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Contribution to the use of new types of carbon paste and fiber electrodes for voltammetric and amperometric determination of 5-amino-6-nitroquinoline and resveratrol
Němcová, Lenka ; Zima, Jiří (advisor) ; Vytřas, Karel (referee) ; Navrátil, Tomáš (referee)
7 ABSTRACT (EN) This dissertation thesis is focused on the study of electrochemical properties of new types of carbon paste electrodes (CPE) and carbon fiber rod electrodes (CFRE), which were used for the development of new highly sensitive and selective voltammetric and amperometric methods for the determination of 5-amino-6-nitroquinoline and trans- and cis- isomers of resveratrol. The carbon paste electrodes were compared in terms of size of the microparticles of glassy carbon contained in the paste (diameters 0.4 - 12 µm; 10 - 20 µm; 20 - 50 µm) in comparison with carbon paste electrode consisting of crystalline graphite and solid glassy carbon electrode. The electrochemical properties were tested using potassium hexacyanoferrate in an aqueous supporting electrolyte and 5-amino-6-nitroquinoline (5A6NQ) in a mixed methanol-water supporting electrolyte. The carbon paste electrode was further used in an amperometric detector of a wall-jet type connected in series with a spectrophotometric detector for the development of a new HPLC method with electrochemical detection and spectrophotometric detection for the determination of trans-resveratrol and cis-resveratrol in samples of grains, hulls and leaves of common and tartary buckwheat. The method was optimized and used for the determination of resveratrol in...
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Voltammetric determination of 4-aminopyridine
Kudláčková, Kateřina ; Zima, Jiří (advisor) ; Fischer, Jan (referee)
In this thesis, the voltammetric behavior of 4-aminopyridine was investigated using carbon paste electrode. Differential pulse voltammetry was used for the study. Measurements were carried out in Britton-Robinson butter medium with different pH values. Optimal pH value found was 9. The electrode passivation during consecutive measurements of 4-aminopyridine without the surface renewal was confirmed, while the accumulation time had no influence on peak heights of 4-aminopyridine. Limit of detection was 8,76×10-6 mol dm-3 and limit of quantification was 1,85×10-5 mol dm-3 of 4-aminopyridne under optimal conditions. The linearity of the calibration curve was evaluated using the correlation coefficient.
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Contribution to the use of new types of carbon paste and fiber electrodes for voltammetric and amperometric determination of 5-amino-6-nitroquinoline and resveratrol
Němcová, Lenka ; Zima, Jiří (advisor) ; Vytřas, Karel (referee) ; Navrátil, Tomáš (referee)
7 ABSTRACT (EN) This dissertation thesis is focused on the study of electrochemical properties of new types of carbon paste electrodes (CPE) and carbon fiber rod electrodes (CFRE), which were used for the development of new highly sensitive and selective voltammetric and amperometric methods for the determination of 5-amino-6-nitroquinoline and trans- and cis- isomers of resveratrol. The carbon paste electrodes were compared in terms of size of the microparticles of glassy carbon contained in the paste (diameters 0.4 - 12 µm; 10 - 20 µm; 20 - 50 µm) in comparison with carbon paste electrode consisting of crystalline graphite and solid glassy carbon electrode. The electrochemical properties were tested using potassium hexacyanoferrate in an aqueous supporting electrolyte and 5-amino-6-nitroquinoline (5A6NQ) in a mixed methanol-water supporting electrolyte. The carbon paste electrode was further used in an amperometric detector of a wall-jet type connected in series with a spectrophotometric detector for the development of a new HPLC method with electrochemical detection and spectrophotometric detection for the determination of trans-resveratrol and cis-resveratrol in samples of grains, hulls and leaves of common and tartary buckwheat. The method was optimized and used for the determination of resveratrol in...
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Determination of sulfamethizole using carbon paste electrodes
Mikeš, Miroslav ; Zima, Jiří (advisor) ; Vyskočil, Vlastimil (referee)
The proposed Thesis deals with the electrochemical behavior of sulfamethizole on carbon paste electrodes. Sulfamethizole is a sulfonamide antibiotic effective against a number of gram-positive and gram-negative bacteria. In human medicine, the most frequent application is for the treatment of urinary tract. In veterinary medicine, it is used for the and preventive treatment of both aquatic and terrestic animals. Due to the wide utilization and low metabolization, it also presents an environmental burden. The development of quick and sensitive methods for the determination in both biological and pharmaceutical matrices is therefore important. This Thesis deals with the search of optimum conditions for differential pulse voltammetric determination of sulfamethizole in tablets Micturol sedante, used for the treatment of urinary tract. The method uses Britton-Robinson (B-R) buffer pH 7 and reaches detection limit 0,39 µmol·l-1 . Results of the method complied with the manufacturer's information and with the results of spectrophotometric determination. In the other part of the work, conditions for the determination of sulfamethizole determination in urine samples. Fonund conditions were: Lichrospher® RP-18, 100 (5 µm), 125×4 mm, (LichroCART) column, mobile phase B-R buffer pH 3 : methanol (7:3, v/v) and...
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