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Determination of aminoglutethimide using HPLC-ED on carbon pastes
Vlachová, Karolína ; Zima, Jiří (advisor) ; Šestáková, Ivana (referee)
In this thesis, the determination of AGT, sooner used as anticancer drug, especially for the treatment of breast cancer in postmenopausal women or for the treatment of prostate cancer, by high performance liquid chromatogramy with UV spectrophotometric detection (HPLC-UV) and electrochemical detection (HPLC-ED) on carbon paste electrodes (CPEs) was studied. CPEs were prepared from glassy carbon microspheres and different pasting liquids - routinely used mineral oil (CPE-MO) and less commonly used tricresylphosphate (CPE-TCP) and silicone oil (CPE-SO). The concentration dependences of AGT were measured by HPLC-UV with detection wavelength 242 nm, by HPLC-ED with a working potencial of +1,3 V for CPE-MO and + 1,1 V for CPE-TCP in mobile phase containing phosphate buffer (pH 4) and methanol 50:50 (v/v). The following limits of detection were achieved - 3,6. 10-7 mol.l-1 for UV spectrophotometric detection, 2,5. 10-7 mol.l-1 for electrochemical detection with CPE-MO and 9,7. 10-7 mol.l-1 for electrochemical detection with CPE-TCP. AGT was also determined in model samples of urine. With HPLC-UV it was not possible to detect AGT, because of the interferences of other compounds. With HPLC-ED on CPE-MO the limit of detection 5,2. 10-7 mol.l-1 AGT was achieved. KEY WORDS Aminoglutethimide HPLC with UV...
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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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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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Determination of aminoglutethimide using HPLC-ED on carbon pastes
Vlachová, Karolína ; Šestáková, Ivana (referee) ; Zima, Jiří (advisor)
In this thesis, the determination of AGT, sooner used as anticancer drug, especially for the treatment of breast cancer in postmenopausal women or for the treatment of prostate cancer, by high performance liquid chromatogramy with UV spectrophotometric detection (HPLC-UV) and electrochemical detection (HPLC-ED) on carbon paste electrodes (CPEs) was studied. CPEs were prepared from glassy carbon microspheres and different pasting liquids - routinely used mineral oil (CPE-MO) and less commonly used tricresylphosphate (CPE-TCP) and silicone oil (CPE-SO). The concentration dependences of AGT were measured by HPLC-UV with detection wavelength 242 nm, by HPLC-ED with a working potencial of +1,3 V for CPE-MO and + 1,1 V for CPE-TCP in mobile phase containing phosphate buffer (pH 4) and methanol 50:50 (v/v). The following limits of detection were achieved - 3,6. 10-7 mol.l-1 for UV spectrophotometric detection, 2,5. 10-7 mol.l-1 for electrochemical detection with CPE-MO and 9,7. 10-7 mol.l-1 for electrochemical detection with CPE-TCP. AGT was also determined in model samples of urine. With HPLC-UV it was not possible to detect AGT, because of the interferences of other compounds. With HPLC-ED on CPE-MO the limit of detection 5,2. 10-7 mol.l-1 AGT was achieved. KEY WORDS Aminoglutethimide HPLC with UV...
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