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Influence of Cadmium on its Metabolism and Changes of Content of Nutritionally Important Compounds in Spring Barley
Paznocht, L. ; Vodičková, H. ; Phuong, L. M. ; Nováková, Kateřina ; Zámečníková, B. ; Kotíková, Z. ; Miholová, D. ; Navrátil, Tomáš
Very important agriculture products are cereals, which significantly contributes to securing of human nutrient needs. Cadmium is a toxic heavy metal, which is readily taken up and accumulated by plants in spite of its harmful effects. This metal cause a stress for the plants and results in many morphological, anatomical, physiological and biochemical changes. The effect of cadmium on the plant metabolism and changes in the content of nutritionally important compounds (protein and some metals – Fe, Zn, Cu, Mn content) was investigated. Results shown, that cadmium was effectively retained in the roots and content of studied compounds was influenced by present of cadmium in nutrient medium. In all the parts of cadmium-treated seedlings decrease in the iron content and increase in the zinc content (except of the first leaves) and decrease in the manganese content was found. The copper content in the root tissue increased by 112.1 %, on the other hand a significant decrease (by 44.4 % and 40.9 % respectively) in the first and the second leaves was observed. In the experimental varieties with cadmium in the concentration of 10-5 mol L-1, the content of soluble proteins was determined statistically higher in the root and basal parts than in the controlled varieties.
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Use of Silver Solid Amalgam Electrode for Determination of Acaricide Amitraz
Nováková, Kateřina ; Harvila, M. ; Navrátil, Tomáš ; Zima, J.
The electrochemical behavior of amitraz was studied at polished (p-AgSAE) and mercury meniscus modified (m-AgSAE) silver solid amalgam electrodes. The reaction mechanism was investigated using direct current voltammetry (DCV) and elimination voltammetry with linear scan (EVLS). The optimum conditions for differential pulse adsorption stripping voltammetry (DPAdSV) determination of amitraz were found in Britton-Robinson (BR) buffer mixed with ethanol in a volume ration of 1:4. DPAdSV with optimized parameters was applied for determination of amitraz in analyzed solutions. The limits of detection were calculated as 8.9 nmol L-1 (tacc = 20 s) for m-AgSAE and 0.168 mol L-1 (tacc = 20 s) for p-AgSAE. The proposed method was successfully applied for determination of this compound in real sample solutions.
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Information on Several Interesting Case Reports of Liquid Mercury Intoxication
Navrátil, Tomáš ; Vlčková, Š. ; Mrázová, K. ; Nováková, Kateřina ; Zakharov, S. ; Honsová, Š. ; Pelclová, D.
This contribution reports on several mercury non-professional intoxications. It can be summarized that it is very important to differentiate among forms of mercury which can (acute or chronic) endanger human health. Contrarily to the wide spread fears, liquid mercury represents low danger for men and for environment. Solid amalgams are probably the less toxic forms of mercury compounds. On the other hand, widely spread daily consumer goods can be very dangerous and toxic (saving balls, fluorescent tubes, etc.). Moreover, these goods are not marked as “toxic mercury containing”. The article discusses the instruction for removing mercury from our environment. Most of the reported data are based on database of the Czech Toxicological Information Centre (TIC) (from the years 1995 – 2015).
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Unique Properties of Amalgam Electrodes
Josypčuk, Bohdan ; Josypčuk, Oksana
Depending on metal-mercury ratio and on the method of preparation amalgam can be: 1) solid compact; 2) paste; 3) liquid; 4) monocrystalline; 5) porous; 6) powdered. High potential of hydrogen overvoltage is observed on amalgam electrodes and it is comparable with one on Hg-electrodes. Another important benefit is the possibility to prepare amalgam electrode, detector or reactor of required size and shape. From amalgams have been prepared and tested many types of electrodes for batch and flow-through systems. The diversity of amalgam materials provides some unique electrochemical properties of electrodes, the most important of which are described in this paper.
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Isolation and Characterization of Protoplasts and their Utilization for Model Membrane
Nováková, Kateřina ; Navrátil, Tomáš ; Šestáková, Ivana ; Langmaier, Jan ; Heyrovský, Michael ; Zámečníková, B. ; Vodičková, H.
Protoplasts are prepared form plant cells by removing their cell walls, which are usually destroyed mechanically or by enzymes. Protoplasts exhibit the spherical shape after removing of their cell walls. They can be isolated from a range of plant tissues: leaves, stems, roots, anthers, and even pollen. Plasmatic membranes surrounding protoplasts can be used as a source of model membranes. Therefore, some parts of plasmatic membranes or subcellular organelle membranes, which contain specific transport systems, can be isolated and integrated to model phospholipid membranes. State of such model membranes can be characterized by electrochemical impedance spectrometry (EIS) and the transported species can be determined with the use of voltammetric methods.
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Use of the Silver Solid Amalgam Electrode for Determination of 5-Nitroindazole
Nováková, Kateřina ; Navrátil, Tomáš ; Hrdlička, V. ; Vyskočil, V. ; Barek, J. ; Chýlková, J.
The voltammetric behavior of 5- nitroindazole (5-NI) has been investigated using mercury meniscus modified (m-AgSAE) silver solid amalgam electrode (inner diameter 0.5 mm). Differential pulse voltammetry (DPV) and cyclic voltammetry (CV) were used for study of electrochemical behavior of 5-NI. Britton-Robinson buffer was found to be the best available supporting electrolyte for 5-NI determination. The reaction mechanism was investigated by CV and by elimination voltammetry with linear scan (EVLS). DPV with optimized working parameters was applied for analysis of model solutions containing 5-NI. The limit of detection was calculated as 0.14 mol L for m-AgSAE. Proposed method was successfully tested for analysis of real water samples spiked by 5-NI.
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