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  • Author or Editor: B. Myasoedov x
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Abstract  

New methods for separation and determination of actinides, widely used in analysis of actinides in technological and environmental samples are reviewed. Special attention is paid to obtaining and stabilizing transplutonium elements. (TPE) in extreme oxidation states. Their use in analytical practice resulted in expanding possibilities of methods for separation and determination of TPE. Solvent extraction, sorption and extraction chromatography are the basic methods for separation of TPE. Solvent extraction, sorption and extraction chromatography are the basic methods for separation of TPE. Methods of separation in gas phase and some other methods such as precipitation and coprecipitation are applied, however, to a lesser degree. Trends of development of these methods including those of various types of membrane extraction that succeeded in separation of TPE in both trivalent and other valence states have been shown. Attention is paid mainly to consideration of modern methods for determination of actinides, special distinction of such methods being low limits of determination, high precision and selectivity. Alpha- and beta-spectrometric methods with semiconductor detectors are the most advanced among various methods based on registration of nuclear radiation. Tremendous success has been achieved in development of emission-spectrometric methods for determination of trace amounts of actinides and various impure elements occurring in samples of actinides. Sensitive mass-spectrometric methods are widely used for determination of both isotope composition and content of elements in various samples including those which are highly radioactive. More simple and precise titrimetric methods based on using oxidizing-reducing or complexing agents are developed successfully. A large number of coulometric methods for determination of americium and berkelium, characterizing high precision and selectivity as well as luminescence methods have been developed.

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Abstract  

This paper desribes the main sources of radioactive contamination of Russia and some techniques elaborated in the V. I. Vernadsky Institute of Geochemistry and Analytical Chemistry for the determination and speciation of radionuclides in the environment. Data on radioecological monitoring of the zone affecting by Production Association “Mayak” are presented as example of the use of these techniques. Some problems of the calculation of radionuclide migration coefficients and the determination of their so called geochemical forms of occurrence are discussed.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: N. Kremliakova, K. Barsukova, and B. Myasoedov

Abstract  

Behaviour of transplutonium and rare-earth elements on TVEX, containing TBP, HDEHP, mixture of TBPHDEHP (11), PAPNA and TOA has been studied. The analytical possibility of isolation and separation of tetravalent Pu and Bk from trivalent actinides and lanthanides from strong nitric acid solutions (1.0–12.0) on TVEX with TBP, POR, HDEHP and TOA has been demonstrated. The separation of trivalent Bk, Cf and Eu from Am and Cm is real on TVEX, containing HDEHP and mixture of TBPHDEHP.

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Abstract  

Extraction of actinides has been examined in two-phase aqueous systems based on poly(ethylene glycol) (PEG) from sulfate solutions in the presence of potassium phosphotungstate, which forms strong complexes with ions of tri- and tetravalent transuranium elements. Extraction of these complexes by aqueous PEG solution is complete in contrast to that of penta- and hexavalent actinides. Conditions have been chosen for the separation of actinides in different oxidation states.

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Abstract  

The interaction of short-lived Rn-daughter products /SLDP/, viz.214Pb and214Bi dissolved in sea-water with Fe/III/ hydroxide colloids followed by flotation of combined Fe-SLDP particles at the sea-air interface subsequently generating marine aerosols enriched in214Bi and214Pb have been studied under laboratory conditions. Rate constants for attachment of214Bi and214Pb to dispersed Fe/III/ colloids in the sea water are found to be 3.7×10–4 min–1 litre [g/Fe/]–1 and 2.4×10–4 min–1 litre [g/Fe/]–1, resp., /20°C/ over the concentration range of iron /III/ from 8 to 120 g liter–1. The suggested mechanism of colloid flotation and aerosol generation might be responsible for some peculiarities of SLDP distribution in the lower marine atmosphere.

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Abstract  

Extraction chromatographic behaviour of cesium, barium and strontium on TVEX impregnated by crown-ether dicyclohexyl-18-crown-6 was studied. Data obtained were used as the base of the technique of radiostrontium isolated from environmental objects.

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Abstract  

The forms of Chemobyl plutonium were determined in soils with model laboratory and field experiments.

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Abstract  

Extraction of trivalent lanthanides and actinides by primary amines from nitric acid solution in presence of potassium phosphotungstate (K10P2W17O61) has been investigated. The effect of nitric acid, potassium phosphotungstate and extractant concentrations, of the organic solvents and the length of primary amine alkyl chain has been studied. Primary amines in chloroform can be used for separtion of lanthanides and actinides and their group isolation.

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Abstract  

The sorption of protactinium on chelating resins, containing arsono groups, or other salt-forming groups on an aminopolystyrene lattice, is discussed. The chelating resins were synthesized by coupling diazotizedp-aminopolystyrene witho-hydroxyphenylarsonic acid, 2-arsonobenzene-(1-azo-2)-1,8-dihydroxynaphthalene-3,6-disulphonic acid (Arsenazo I) and some other monoazo derivatives of chromotropic acid. The dependence of sorption of Pa, Zr, Nb and Ta was investigated from hydrochloric acid and sulphuric acid solutions under static conditions as a function of the concentration of the acid. The feasibility of separating Pa from Fe, U, Zr, Nb, Th and Po is shown, using a solution 10N in respect to sulphuric acid and 0.3M in respect to oxalic acid and employing a resin obtained by coupling diazotized aminopolystyrene with Arsenazo I.

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