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Abstract  

The simultaneous substoichiometric separation of europium and terbium is presented and its application to the determination of these elements with DTPA and HTTA is developed. Experimental results for the simultaneous substoichiometric separation are in good agreement with the theoretical results introduced by the principle. Europium and terbium in orchard leaves are determined by simultaneous substoichiometric neutron activation. The analytical values are 23±1.1 ppb for europium, and 17±1.2 ppb for terbium.

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Abstract  

The sorption of small amounts of europium(III) on iron(III) hydroxide and oxide has been studied as a function of pH. The mechanism of sorption is discussed. Optimum conditions have been found for the preconcentration of small or trace amounts of europium(III) by iron(III) hydroxide and oxide. The influence of complexing agents (EDTA, oxalate, tartrate and 5-sulfosalicylic acid) on the sorption of small amounts of europium(III) on iron(III) oxide has also been studied.

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Abstract  

Eu-151 Mössbauer spectra of tetrakis/diethyldithiophosphato/europium/III/ compounds suggests substantial electron transfer from dithiophosphate ligand to europium. The photochemical reaction of these complexes was investigated in organic solutions, and it was demonstrated that the Mössbauer isomer shift was correlated with their 420 nm band.

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Abstract  

EuCl3 was applied intravenously /1 mg kg–1 body weight/ to chicken. Tissue samples of chicken /blood, liver, spleen, fat, pancreas, kidney, lung, breast muscle, brain, femur, testes/ were analyzed for europium concentration. High europium concentrations were found in liver /54.08 ppm/, in spleen /16.44 ppm/ after 24 h and femur /3.28 ppm/ 7 d after application. This experiment shows that accumulation of europium occurs in the yolk of eggs after application of EuCl3 to egg-laying hens /1 mg kg–1 body weight/ during 37 d.

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Abstract  

The151Eu Mössbauer spectra were measured of surface-oxidized europium/II/ sulfate with the γ-ray transmission- and conversion electron technique. The comparison of such spectra demonstrated that the change in the oxidation state of trace amounts of europium induced by surface reactions could be characterized by the conversion electron Mössbauer technique. The photochemical reduction of europium/III/ oxalate to a Eu/II/species after irradiation with a low-pressure mercury lamp was demonstrated by means of this technique as well as ESR.

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Abstract  

Complexation of trivalent europium by a well characterized soil fulvic acid was investigated by equilibrium dialysis titration method ([FA]=24 mg·dm–3, [Eu]t=9.0·10–7–3.5·10–6 mol·dm–3, pH 6.0). The concentrations of the fulvate bound and free europium were measured radiometrically using152Eu as a tracer. The experimental results were evaluated using a bimodal normal distribution model and a plot with two overlapping normal distributions was obtained which gave two means logKI=7.0, I=1.1; µII=4.9, II=0.5) values for binding of europium by two classes of sites in fulvic acid. A multiligand model was assumed for fulvic acid, based upon the Eu(III) luminescence studies (7F0 5D0 excitation) on many organic acids as model ligands.

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Abstract  

Theoretical calculation shows considerable cross section for production of145,146Eu through133Cs(16O,xn) nuclear reaction. To reduce the trials with costly particle accelerators beam time experimental simulation for separation of carrier free europium from cesium target matrix has been performed. Trace amounts of152,154Eu have been separated from macro and trace amounts of cesium. A high separation factor has been achieved when 1% HDEHP and 10−3M HCl is used as organic and aqueous phase respectively. Trace europium has been successfully back extracted into HCl, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) medium.

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Abstract  

New lanthanoid-iron complexes having phenanthlorine as the chelating ligand were synthesized and characterized by151Eu- and57Fe-Mössbauer spectroscopy. The temperature dependence of the area intensity of Mössbauer lines of europium complexes (single crystals) has been correlated to the state of molecular association in the solid state. The crystal structure of europium complex, {[Eu(phen)2(H2O)2][(μ-NC)2 Fe(CN)4]·2phen]}x was determined by X-ray crystal analysis. This complex consists of one-dimensional zig-zag chain structure.

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Summary  

The extractive properties of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(diphenylphosphinoylmethoxy)calix[4]arene towards thorium(IV) and europium(III) ions are studied. The conventional log-log analysis of the extraction data reveals that the stoichiometry of the extracted species is 1 : 1 metal ion to ligand ratio for the two metals. The effects of ligand concentration, types of diluent and concentration of the salting-out agents are investigated and discussed. The selectivity of the ligand for thorium and europium ions versus Mn2+, Pb2+, Cd2+, Fe2+, Ni2+ and Co2+ is examined.

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Abstract  

The extraction behavior of Eu(III) has been studied using di(2,4,4-trimethylpentyl)phosphinic acid (DTMPPA, HA) in kerosene. Europium was extracted as Eu(HA2)3 with the extraction constant of 2.0·10–3. This extraction system was applied to the transport of Eu(III) across a DTMPPA liquid membrane supported on porous polytetrafluoroethylene. Europium was quantitatively moved through the liquid membrane containing 0.1M (HA)2 as a mobile carrier from the feed solution of pH above 3 into the product solution of 0.1M HNO3, yielding a concentration factor of ten. The transport rate increased with increasing pH and DTMPPA concentration.

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