|
| |
|
| |
|
| |
|
|
Optimization of a Flow Rate for a Hyphenation of Voltammetry with Electrospray Ionization Mass Spectrometry
Jaklová Dytrtová, Jana ; Jakl, M. ; Norková, Renáta ; Navrátil, Tomáš
The hyphenation of an electrochemical cell prior to mass spectrometer with electrospray ionization allows studying of products and/or of intermediates of electrode reactions. The measurement is realized in a flowing system. The flow rate of the sample markedly influences the MS signal intensity of the product. The calculated optimum value for the electrochemical cell with the sweep volume 0.72 μL is in the range from 0.4 to 0.5 mL h -1 . The experimental optimal value is 0.45 mL h -1 . The optimization of the flow rate has to be provided individually for each product, because the intensity also depends on the rate of the electrode reaction and product stability.
|
|
| |
|
|
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.
|
|
|
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.
|
|
|
Vliv vápnění na biopřístupnost mědi a její příjem olší
Jakl, M. ; Kuneš, I. ; Jaklová Dytrtová, Jana ; Balaš, M. ; Tlustoš, P.
Přijatelnost mědi na horské lesní půdě (7 let po hnojení) zalesněné olší (Alnus incana (L.) Moench) byla zkoumána pomocí techniky difúzního gradientu v tenkém filmu (DGT) v porovnání s její vodorozpustnou frakcí v půdě a obsahem v jednotlivých částech rostlin. DGT se zdá jako slibnější metodou stanovení přijatelnosti prvků, koreluje s celkovými koncentracemi v rostlinách více než koncentrace ve vodném výluhu půdy. Hnojení zvýšilo koncentraci Cu v nejtenčí kořenové frakci; celková množství v ostatních frakcích hnojené olše byly signifikantně vyšší než u kontroly.
|
|
| |
|
|
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.
|
host ::
RSS.