A. Bumbálová

Ecotoxicological effects and uptake of metals (Cu+, Cu2+, Mn2+, Mo6+, Ni2+, V5+) in freshwater alga Scenedesmus quadricauda

Abstract The ecotoxicological effects of six metals (Cu+, Cu2+, Mn2+, Mo6+, Ni2+, V5+) expressed as growth inhibition, respiratory rate, and total chlorophyll, chlorophyll a and b contents by alga Scenedesmus quadricauda were determined. Besides these parameters, the uptake of tested metals by alga was determined by using RXFA. On the base of the calculated EC50 values, the following rank orders of inhibition were arranged: for algal growth: Cu2+>Cu+>Ni2+>V5+-Mo6+>Mn2+; for total chlorophyll content: Cu2+>Ni2+>Cu+>Mn2+>V5+>-Mo6+; for chlorophyll a content: Cu2+>Ni2+>Cu+>V5+>Mn2+>Mo6+; for chlorophyll b content: Cu 2+=Cu+>Ni2+>Mn2+>Mo6+>-V5+. Respiratory rate was measured for metal concentrations corresponding with EC50 values for growth inhibition by oxygen electrode. The most intensive respiration was observed for V5+ and less for Mo6+. When the uptake of metals from the medium was determined, in the highest percentage were uptaken Ni2+ (20%), Cu2+ (17,6%) and Mn2+ (15,19%). Other metals were only uptaken in the amounts lower than 5.5 % from the metal concentration added into the cultivation medium. For uptake determination as well as for respiratory rate measurements, concentrations corresponding with calculated EC50 values for growth inhibition were used.

The effect of Cu(II) ions bound with tridentate Schiff base ligands upon the photosynthetic apparatus

Summary The effect of diaqua-(N-pyruvidene-β-alaninato) copper (II) monohydrate (Cu(pyr-β-ala)) on the photosynthetic apparatus of spinach chloroplasts was investigated. It was found that Cu(pyr-β-ala) inhibits the photosynthetic electron transport in chloroplasts due to its interaction with the photosynthetic centers. Its sites of action have been determined to be not only the intermediate Tyr Z (reported by Schroder et al., 1994), but also the intermediate Tyr D , which are situated in D 1 and D 2 proteins on the donor side of PS 2. The interaction of Cu(pyr-β-ala) with these intermediates was manifested by a decrease of the intensity of EPR signals II slow and II very fast , respectively, in chloroplasts treated with Cu(pyr-β-ala). The appearance of lines corresponding to Mn 2+ ions in EPR spectrum of Cu(pyr-β-ala)-treated chloroplasts and simultaneous disappearance of the manganese band in spectra of band radionuclide X-ray fluorescence analysis (RFA) confirm that a further site of Cu(pyr-β-ala) action is the manganese cluster in the oxygen evolving complex (OEC) on the donor side of PS 2. One of the suggested mechanisms of action of Cu(pyr-β-ala), namely chelatation of its copper(II) ions with tryptophan and tyrosine constituents of proteins situated in photosynthetic centres, has been confirmed by the results of fluorescence studies (quenching of the emission bands of the above mentioned aromatic amino acids in the presence of Cu(pyr-β-ala)) and EPR spectroscopy (differences in the form of spectra of Cu 2+ ions corresponding to the dissolved Cu(pyr-β-ala) and to chloroplast-trapped Cu 2+ ions of this compound). The second suggested mechanism of action of Cu(pyr-β-ala) is the substitution of manganese and calcium ions present in OEC by copper, which was confirmed by the intensity decrease of their bands (channel numbers: 91, 106 for Mn and 39 for Ca) in RFA spectra of Cu(pyr-β-ala)-treated chloroplasts and simultaneous increase of the intensity of corresponding bands belonging to Cu (channel numbers: 146, 168).

Heavy metals and some other elements in medicinal plants. Determined by X-ray fluorescence analysis

Determination of Mn, Fe, Cu, Zn, Hg, Pb, Br, Se, Rb, Sr and Cd in the medicinal plants by radionuclide X-ray fluorescence analysis (using238Pu,241Am/Ag and125I) is described.

Identification of elements in plant drugs and their water infusion using X-ray fluorescence analysis

The present work gives preliminary results of analysis of drug mixtures (NEPHROSAL tea bag) and its water infusion. In a sample of dried drugs the elements K, Ca, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Pb were identified, whereas in their water infusion only Ca, Mn, Zn and Sr were found. The method applied was radionuclide X-ray fluorescence analysis using a radionuclide source109Cd, a Si/Li semiconductor detector and a multichannel analyzer Canberra 8100.

Multielement XRF-analysis of blood from patients with dilated cardiomyopathy

The radionuclide X-ray fluorescence analysis was used for the determination of Fe, Zn, Br and Rb levels in whole blood from dilated cardiomyopathy patients and matched control subjects (from Bratislava). The XRF-system consisted of a radionuclide source109Cd, a semiconductor Si/Li detector connected to a multichannel analyzer.

Preparation of99mTc complexes with compounds structurally related to ethylene diamine tetraacetic acid

The preparation of99mTc-Sn-DOTA,99mTc-Sn-DDDTA and99mTc-Sn-DHDTA is described. The labelling efficiency of all samples was checked by paper chromatography, thin layer chromatography and paper electrophoresis. Preliminary results of the biodistribution studies performed in white rats are given.

In situ spin trapping of •OH radicals photochemically generated by thiophene oligomers incorporated in copper-doped ZSM-5 zeolite in aqueous medium

Abstract The formation of reactive oxygen species due to irradiation by visible light of thiophene oligomers incorporated in the pentasile-type Na-ZSM-5 zeolite microstructure has been studied in aqueous medium. The oxidative oligomerization of thiophene was carried out in the zeolite channels after ion exchange of Na + for Cu 2+ . By means of spin trapping, the hydroxyl radicals temporarily produced in situ were detected by EPR spectroscopy in aqueous suspension on the Cu-ZSM-5 sample with polythiophene deposited in the channels of the zeolite microstructure during illumination with visible light.

Metal bioaccumulation by the freshwater algaScenedesmus quadricauda

Bioaccumulation of six metals (Cu2+, Cu+, Mo6+, Mn2+, V5+, Ni2+) and their combinations by algaScenedesmus quadricauda was determined by using radio nuclide X-ray fluorescence (RXFA). The metals were added into the cultivation medium in concentrations corresponding with EC50 value for each metal. The obtained results indicate that Ni2+, Cu2+ and Cu+ were accumulated in high amounts (20%, 17.5% and 15.19%) the Mo6+ ion (<0.2%) was accumulated in the lowest amount. For metal-metal interactions in accumulation of metal ions by algaS. quadricauda three types of answers were determined: inhibition (Mo→Cu2+, Ni, Mn, V; V→Ni, Mn; Mn→Ni, Cu2+, Cu+; Cu+→Ni; Cu2+→Ni; Ni→Mn, V), enhancement (V→Cu+; Cu2+→Mn;Cu+→V, Mn; Mn→V; Ni→Cu2+, Cu+) and neutral effect (V→Mo; Cu2+→Mo; Cu+→Mo; Mu→Mo; Ni→Mo).

Radionuclide X-ray fluorescence analysis of drinking water using preconcentration of trace metals on chelating cellulose exchanger OSTSORB-OXIN

Determination of Cr, Fe, Cu, Zn and Pb in drinking water preconcentrated on a chelating ion exchanger of Czechoslovak production is described. The analytical system consisted of a radionuclide source238Pu, a Si/Li semiconductor detector and a multichannel analyzer. Results are compared with trehshold limit values recommended for drinking water.

Biological distribution of99mTc-EDTA derivatives

Biodistribution of EDTA derivatives99mTc-Sn-DOTA, DDDTA, DHDTA /1,2-dinitriloalkane-tetraacetic acids/ individually and bound to liposome in rats is described. The obtained results are compared with99mTc-Sn-EDTA.