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  • Author or Editor: L. Guseva x
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Abstract  

A simple and effective tandem generator system (anion- and cation-exchange columns connected successively) on production of 223Ra and 211Pb/211Bi in DTPA solutions suitable for biomedical studies has been developed. 223Ra was repeatedly separated from parent radionuclides 227Ac and 227Th, sorbed on anion-exchange column (generator 1), and is loaded directly on cation-exchange column (generator 2) from HNO3/CH3OH solutions. Cation-exchange behavior of Ra and Pb in DTPA solutions was studied in detail. Optimum conditions have been found for repeated isolation of 211Pb/211Bi and 223Ra in form of chelate complexes with DTPA from cation-exchange column (generator 2). The decontamination factor of short-lived descendants from parent radionuclides was ≥106. The system is reliable and easy to use. The advantages of tandem generator system for application in radiotherapy are discussed.

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Abstract  

A new tandem generator system (cation-exchange generator column coupled to anion-exchange), based on the 228Ra as starting radionuclide, for 212Pb/212Bi production in the solutions suitable to direct application in biomedical investigations has been developed. Optimum conditions have been found for retention of Ra, Th and Ac parent radionuclides on the cation-exchange column and repeated elution of Pb with subsequent concentration on anion-exchange column using HBr and mixed HBr/CH3OH solutions. It was shown that Pb/Bi could be eluted from anion — exchange column with a small volume of EDTA, DTPA, NaCl solutions or heated H2O. The advantages of the tandem generator system for production of short-lived Pb/Bi radionuclides and their application for biomedical studies are discussed.

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Abstract  

The methods of TPE isolation and separation from all accompanying and interfering elements, using only one or two ion-exchange columns and mineral acid solutions are proposed. The difficulties of TPE determination in environmental samples and advantages of the methods are discussed.

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Abstract  

A generator system, consisting of two anion- and one cation-exchange columns for production of medical α-radionuclides 225Ac and 213Bi, has been developed. The first anion-exchange column was used for periodical separation of 225Ac from Th with 8 M HNO3, while the second anion-exchange column was employed for purification of 225Ac from Ra and inactive impurities in mixed HNO3/CH3OH media. From anion-exchange column 225Ac was stripped with 0.1–0.2 M HNO3 and loaded directly onto cation-exchange column, used as a generator for repeated isolation of 213Bi. The cation exchange behavior of Bi and other radionuclides of the interest were studied in diluted HCl, HBr and DTPA solutions used as eluents. As result, a simple and effective method for the production and purification of 225Ac and 213Bi suitable for biomedical studies was elaborated.

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Abstract  

The TPE behaviour on the strongly basic anionite Dowex-1×8 in aqueous—alcoholic solutions of lactic, butyric, iso-α-oxybutyric and α-oxyisobutyric acids in a mixture with nitric acid has been investigated. Distribution coefficients and separation factors of TPE have been determined depending on the content of various components of the mixture. High values of separation factors have been obtained for the pair Am-Cm (∼6) using mixtures of α-oxybutyric and nitric acids as eluents in aqueous—alcoholic solutions. The advantages of using macroporous anionites AB-1710P and AB-29P for TPE separation in such solutions are discussed.

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Abstract  

The behaviour of transplutonium and rare-earth elements on anion and cation exchangers in solutions of H3PO4 and H2SO4 in the presence of oxidants (KBrO3, PbO2, (NH4)2S2O8) and in HCl solutions in the presence of reducing agents [Zn(Hg), Eu2+] depending on acid concentration as well as on oxidant content and nature in solution or in resin and other factors has been studied. Effective methods of Bk(IV), Ce(IV), Am(VI), Eu(II) and Md(II) separation from trivalent TPE and REE, as well as continuous methods of isolation of isotopically pure radionuclides250Bk,144Pr by using ion exchangers and inorganic acid solutions have been developed.

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Abstract  

A simple and effective method has been developed for the continuous production of the short-lived isotope Pb as a homolog of element 114 on the principle of a radionuclide generator. The method is based on the initial sorption of 227Ac or 223Ra on a small cation-exchange column, with subsequent “milking” of 211Pb (36.1 m) by a mixture of HCl/CH3OH. The optimum conditions for the repeated separation of 211Pb from radionuclides strongly sorbed by the cation-exchanger (Ac, Th, Ra, Pu, TPE) have been determined. Possibilities of using the 211Pb generator for test experiments on the solution chemistry of element 114 have been shown. Advantages of aqueous alcohol HCl solutions for the isolation of 211Pb (element 114) are discussed.

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Abstract  

The behaviour of transplutonium elements (TPE) on cation and anion exchangers in aqueous alcoholic solutions of chlorides and nitrates of some alkali and alkaline earth metals as depending on different factors: salt concentration, content of alcohol and of acid in the solution as well as the nature of a cation has been studied. The data obtained were used to determine the optimal conditions of concentration of TPE on ion exchangers from solutions containing great quantities of salts. The advantages of the use of aqueous alcoholic solutions of nitric acid in the isolation of TPE from such solutions have been shown.

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Abstract  

The sorption of transplutonium (TPE), rare-earth (RE) and other elements by anion-exchangers (Dowex 1 type) from aqueous alcoholic solutions of nitric acid and ammonium thiocyanate was investigated. This investigation allowed the development of simple and effective methods of americium—curium separation from frradiated plutonium. Plutonium, TPE (in a +3 oxidation state) and RE are firmly sorbed by the anion-exchanger from 1 M HNO3 in 90% alcohol, Fe, Al and fission products Cs, Sr, Nb, Zr, and Ru pass through the column under these conditions. The RE separation from TPE is achieved by washing the column with 0.5M NH4SCN in 80% alcohol. The column is then washed with 0.5 M HNO3 in 85% alcohol, and americium—curium separation proceeds. Use of this method for recovery of an irradiated plutonium target containing 100 mg Pu, Am and Cm is described.

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Abstract  

The distribution coefficients of californium and other elements between an anion exchange resin and alcohol solutions of nitric acid of different concentrations have been determined. An effective method is suggested for the purification of californium from other elements which are slightly adsorbed when Cf is concentrated on an anion exchanger from 0.5–1.0N solutions of nitric acid containing 95–90% alcohol; Cf is subsequently eluted with a 0.5N HNO3 solution in 85% CH3OH and simultaneously separated from the elements which are strongly adsorbed on the anion exchange resin. Under the chosen conditions the coefficients of californium purification were determined for a number of elements; the values are 5.4·102–1.8·103 for Al, Ca, Fe and ∼103–105 for Am, Pm, Nd, Ce, Pb, Bi and Na, for one cycle.

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