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Use of Copper Solid Amalgam Electrode for Determination of Triazolic Fungicide Tebuvonazole
Nováková, Kateřina ; Navrátil, Tomáš ; Jaklová Dytrtová, Jana ; Chýlková, J.
With the use newly developed mercury meniscus-modified copper solid amalgam electrode (inner diamter 1.5 mm), the voltammetric behavior of fungicide tebuconazole was researched by differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Applying CV and elimination voltammetry with linear scan (EVLS), the reaction mechanism was investigated. The optimum conditions for DPV determination of this triazolic fungucude were identified in Britton-Robinson buffer/methanol (1:1, v/v) of pH 6.3 DPV with optimized parameters (Ein = +400 mV vs. Ag/AgCl/3M KCl, scan rate 20 mV s-1) was used for determination of determination of tebuconazole in analyzed solutions. Application the prolonged time (60 s), the limit of detection 2.10-7 molL-1. The applicability of the developed method was verified on the analysis of the real soil solution sample.
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Investigation of Complexes of Tebuconazole with Zinc
Jakl, M. ; Norková, Renáta ; Navrátil, Tomáš ; Jaklová Dytrtová, Jana ; Balík, J.
Tebuconazole is one of the most utilized triazole pesticides in agriculture. Its stability is highly affected by complexation with metals. Moreover, it creates more or less stable complexes with essential elements that become unavailable to plants. In the system with overbundant tebuconazole, an inert (very stable) complex with Zn was found. Elimination voltammetry wit linear scan was used for revealing of the electrode processes on the mercury surface. The relatively slow kinetically controlled step in tebuconazole/Zn complex formation indication indicates the great ability of Zn-tebuconazole system to react with more ligans. Therefore, multiligand Zn-tebuconazole complexes with other ligands are expected in the nature.
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Uptake and Bioavailability of Copper after Liming of Alder Plantation
Jakl, M. ; Kuneš, I. ; Jaklová Dytrtová, Jana ; Balaš, M. ; Tlustoš, P.
The availability of copper in mountain forest soil (7 years after fertilization) afforested with alder (Alnus incana (L.) Moench) was explored using the diffusive gradient in thin films (DGT) technique compared with its water soluble fraction in soil and its total content in plant compartments. DGT seems to be more promising method determining elements availability; it corresponds with total concentrations in alder tissues closely than contents in water extract. Fertilization increased concentration of Cu in the thinnest root fraction; its total amounts in other tissues of fertilized alders were significantly higher than in the control.
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The study of cadmium - oxalic acid complexes using DPASV and ESI-MS
Jakl, M. ; Jaklová Dytrtová, Jana ; Tlustoš, P.
The combination of DPASV with ESI-MS allows a reliable detection of metal complexes with small organic ligands. The request to exact molecular mass is essential to stoichiometry design simultaneously with low concentration of the analyte in most of biological matrixes. By the analysis of model solution consisting of Cd(NO3)(2) and oxalic acid (OAH(2)) these structures were identified: [Cd(OAH(2))(H2O)(2)](+), [Cd(OAH(2))(H2O)(3)](+), and [Cd(OAH(2))(H2O)(2)(CH3OH)](+). They were also found in soil solution.
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Cd and Pb Speciation in Thlaspi caerulescens Presl Rhizosphere
Jakl, M. ; Jaklová Dytrtová, J. ; Šestáková, Ivana ; Tlustoš, P.
In this study the influence of Thlaspi caerulescens Presl rhizosphere on Cd and Pb complex formation and their total amount in soil solution of contaminated fluvisol from Litavka river alluvium was investigated. The soil solution was sampled from roots surrounding and from bulk behind rhizobag. The content of free Cd and Pb ions was measured by the differential pulse anodic stripping voltammetry in unchanged pH and in pH 2 in rhizosphere and bulk soil. The bimetallic Cd-Pb-oxalic acid complexes were detected in unchanged pH only.
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Patch Clamp Technique – The Tool for Ions Transport across Model and Real Biological Membranes
Navrátil, Tomáš ; Jaklová Dytrtová, J. ; Jakl, M. ; Šestáková, Ivana ; Mareček, Vladimír ; Krůšek, Jan
The project is aimed at the preparation and characterization of model and/or real phospholipid bilayers at stabilized phase boundaries enabling studies of transfer of charged and uncharged species between the two phases. The best way for investigation of inorganic ion transfer is provided by using mercury as one of the phases, in view of the large amount of the relevant electrochemical data available, whereas the transfer of more complex species is better studied in the system of an organic and an aqueous phase stabilized by (agar) gel. The results contribute to the understanding of ion transport across real membranes. Polypeptides and peptides capable forming ionic channels and enabling transport of various ions and molecules across the membranes, will be incorporated into the model membranes. The possibilities of transport of selected compounds across the model membrane will be investigated using cell permeable peptides as well.
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The Use of Electrochemical Stripping Methods for Lead and Cadmium Speciation in Soil Solutions
Šestáková, Ivana ; Jaklová Dytrtová, J. ; Jakl, M. ; Navrátil, Tomáš ; Fojta, Miroslav
Soil solution is an aqueous phase of soil which is affected by plant root systems. The soil solution contains nutrients, organic and inorganic soil substances and also exudates – substances released by plant roots (e.g. low molecular weight organic acids). For the bioaccumulation (transport from soil into plants) the free metal ions and labile complexes contents (usually in trace amounts) in soil solution are important. That is why the electrochemical methods using working electrode preconcentration step, i.e. differential pulse anodic stripping voltammetry, anodic stripping square-wave voltammetry and stripping chronopotentiometry with constant current, are applicable. Mentioned methods combined with the hanging mercury drop electrode were tested for the cadmium and lead speciation possibilities in model and also real soil solutions.
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