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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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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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Method optimization for simultaneous separation of six triazole fungicides in HPLC
Kovač, Ishak ; Martín Miján, P. ; Del Sol Vega Alegre, M. ; Dejmková, H. ; Jaklová Dytrtová, Jana ; Schwarzová, K.
Triazole pesticides are widely used in agriculture against fungi pathogens. Their application is not restricted on just one member of the group, more importantly, the application is usually carried out in the mixture of two or more triazoles. Hence, this work focuses on simultaneous separation and detection of six triazole fungicides: penconazole, tebuconazole, propiconazole, cyproconazole, fenbuconazole, and difenoconazole. Two different columns were tested with different parameters for isocratic and gradient elution in HPLC with UV detector. On Purospher Reverse Phase-18 column with gradient elution isomers of triazoles cyproconazole and propiconazole were successfully separated. However, on this column, there was an overlap of some triazoles. In contrast, the isocratic elution on Kromasil Eternity-5-PhenylHexyl column showed sufficient separation capabilities. In further research, chiral separation of triazoles will be considered using capillary electrophoresis.
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