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Analytical approaches to study group interactions of azole pesticides with important biological active compounds
Kovač, Ishak ; Jaklová Dytrtová, Jana (advisor) ; Száková, Jiřina (referee) ; Navrátil, Tomáš (referee)
This dissertation presents a developed capillary electrophoresis method for analysing residues of triazole fungicides (TAF) from real samples ("Sweet cherry" tomato - Solanum lycopersicum L) and shows its potential application in environmental analysis. The developed method was validated in-house and characterised by a relatively short analysis time and low cost with sufficient LOD and LOQ. As an additional part of this dissertation, which rose from the tomato plants' treatment with TAF, we studied the impact of triazole fungicides on plant development and their impact on biologically active compounds. Determination of TAF residues from tomato peel carried out with capillary electrophoresis. Capillary electrophoresis is a versatile technique with minute amounts of sample required, with high efficiency in separating small molecules, such as selected TAF. The developed method, cyclodextrin-modified micellar electrokinetic chromatography, accomplished a baseline separation of the TAF mixture from tomato peel. The optimal conditions for separation were in the background electrolyte comprised of phosphoric acid and Tris (100 mM concentration, respectively), 20% v/v methanol, with apparent p[H+ ] 4.8. The constituents of the mixed micellar pseudo-stationary phase were ionic detergent sodium dodecyl...
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Interaction of triazole terconazole with copper cations.
Bártová, Kateřina ; Jaklová Dytrtová, Jana (advisor) ; Navrátil, Tomáš (referee)
Terconazole is one of the triazole derivatives with an antifungal effect. It is used locally to treat vaginal yeast infections. Terconazole could interact with copper cations in the vagina or uterus of women, who use an intrauterine device releasing copper cations. Other triazole derivatives in complexes with copper cations differ in their properties like toxicity or mobility. Cu2+ can be reduced in the presence of triazoles, which can lead to a Fenton-like reaction and production of free radicals. Thus, the Cu2+ /Cu+ terconazole system can be potentially dangerous. Stoichiometry, fragmentation and stability of forming complexes were studied with tandem mass spectrometry. The Cu2+ /Cu+ terconazole system was measured within pH range from 4 to 7,2, with a concentration ratio of CuCl2 and terconazole 1:5 to 20:1, with water and ethanol as solvents (1:1). Results suggest that terconazole is partially oxidized in the Cu2+ /terconazole system and that this oxidation depends on the pH of a solution. Apart from oxidized and protonated terconazole, other detected ions and complexes were not significantly influenced by pH. The detection of complexes containing Cu+ is alarming because this could correspond with the occurrence of a Fenton-like reaction. Key words Terconazole, copper cations, complexes,...
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Separation of triazoles from real samples with capillary electrophoresis
Kovač, Ishak ; Jakl, M. ; Šolínová, Veronika ; Jaklová Dytrtová, Jana
The CE has become one of the advantageous tools in fungicides analysis in complex matrices due to its simplicity and separation efficiency. The separation of a group of thee triazole (i.e. penconazole, tebuconazole, and cyproconazole) fungicides was achieved with CD-MEKC with anionic Sg-CD as a selector at pH=4,8. The background electrolyte consisted of TRIS phosphate buffer (50 mmol/L) and 15 mmol/L SDS. The separation was performed on uncoated fused silica capillary with 500/425 mm (total/effective) length under -15 kV separation voltage. Achieved LOD values with this method were: 0,73, 1,88, 0,60, 1,18 (umol/L) for penconazole, tebuconazole, cyproconazole A and B respectively.
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