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  • Author or Editor: S. Nayak x
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Abstract  

Studies on liquid-liquid extraction of trace level cerium and gadolinium,141Ce and153Gd, from HCl and HNO3 media with liquid cation exchanger, HDEHP reveal that a quantitative separation of the elements from an admixture of the two radioisotopes can be achieved with 0.1% HDEHP and 0.01N HCl. The condition is also valid for separation of trace amount of153Gd from bulk or macro quantity of cerium.

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Abstract  

A comprehensive review has been made to discuss the role of various radionuclides of lanthanide series elements in the field of nuclear medicine. The role of several pharmaceuticals labeled with radiolanthanides and used for investigative purposes like measurement of cerebral blood flow, bone density measurement, bone marrow imaging, etc., have been described. The role of lanthanide radionuclides in radiation synovectomy, radioimmunotherapy, etc., have also been discussed. Methods of preparation of some representative radiopharmaceuticals like153Sm-EDTMP,153Sm-HYP, have been presented. An outline on the production of carrier free radioisotopes of lanthanide series elements has been given.

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Summary  

Studies on adsorption behavior of heavy radionuclides, present altogether in no-carrier-added state, e.g., 197-200Pb, 197-200Tl and 197Hg, have been carried out with calcium alginate beads. High lead (100%) and moderate thallium removal (~65%) was achieved in pH range 2-7. 100% mercury removal was also achieved at pH 2 and 4. Effort has been made to recover all three radionuclides adsorbed in the calcium alginate beads using various chemicals, such as HCl, thiourea, sodium acetate, sodium oxalate and sodium nitrite. It was found that 0.1M HCl and 0.1M thiourea could remove at pH 1 80-90% of adsorbed Pb. Tl recovery was possible by all chemicals mentioned above. Hg was also recovered by all chemicals except HCl.

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Abstract  

The concept of tracer packet, which can be defined as a group of carrier-free radioactive isotopes of few elements, which have been produced together with an objective to study some particular physical, chemical or biological systems has been introduced in this paper. The tracer packet can be produced with low projectile energy (5-7 MeV/u) contrary to the multitracer technique. A thick cobalt foil has been irradiated consecutively with 16O, 7Li and 12C beams to produce the tracer packet containing carrier free radiotracers of Mn, Cu, Zn, Ga, Ge, As and Se which after removal of bulk cobalt can be used for further studies of essential micro nutrient elements.

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Abstract  

Tracer packet, a group of carrier-free radioactive isotopes of few elements which are produced together with an objective to study some particular physical, chemical or biological systems is a new conception over the century old tracer technique and a decade old multitracer technique. This paper describes the production of a tracer packet of heavy and toxic metals containing carrier-free radionuclides of some heavy and toxic elements like mercury, thallium, lead, bismuth and polonium produced by medium energy 7Li and 12C irradiation on gold target and subsequent separation of bulk gold from the carrier-free products.

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Abstract  

Irradiation of natural lutetium oxide target with 7Li beam results in the formation of no-carrier-added 177W radionuclide in the matrix. An efficient radiochemical procedure for the separation of no-carrier-added (nca) 177W (T 1/2 = 2.21 h) radionuclide is presented using liquid-liquid extraction (LLX). A high separation factor between nca 177W from the target Lu has been achieved with 0.1 M TOA and 8 M HCl. About 85% of 177W has been extracted in the organic phase keeping Lu in the aqueous phase in a single run. Using this production and separation method radiochemically pure 177W can be obtained. The separation has also been tried with a greener approach viz. aqueous biphasic extraction. In this case, aqueous biphasic extraction is not a good method for separation of 177W. The radionuclide 177W thus obtained can be used to study the extraction pattern of lighter homologue of the element 106 (Sg) together with Mo, which in turn is important to investigate the chemistry of Sg.

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Abstract  

No-carrier-added 93mMo radionuclide with high specific activity is a potential candidate radionuclide in the field of nuclear medicine due to its suitable half-life and gamma energy with significant intensity. In the present paper, we report the immobilization of radioisotopically and radiochemically pure no-carrier-added (nca) 93mMo onto calcium alginate biopolymer. The experiment has been performed to examine the possibility of polymeric delivery of 93mMo radionuclide by measuring the adsorption of 93mMo on calcium alginate beads. Maximum adsorption was found at pH 2.

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Abstract  

The paper describes the production of a tracer packet of heavier rare earth elements containing carrier-free radionuclides of 153,155Tb, 153,155,157Dy, 159Ho, 159,161Er, 161Tm produced by medium energy 7Li and 12C irradiation on an europium oxide target and the subsequent separation of bulk europium from the carrier-free products.

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Abstract  

Carrier free promethium was produced by proton activation in neodymium target. Extraction behavior of both the elements were studied by HDEHP. A pronounced synergism had been observed by the binary mixture of HDEHP and PC88A. Presence of H2O2 in aqueous phase also increases the separation factor.

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