Effective separation of the congeneric pair of elements, zirconium and hafnium and also niobium which was in admixtures with zirconium as daughter in its isotopic form were achieved through reversed phase column and paper extraction chromatographic procedures using di-(2-ethylhexyl)phosphoric acid (HDEHP) as the liquid exchanger. In reversed phase column chromatographic separation, the tracers,95Zr,95Nb and175,181Hf, were extracted by HDEHP impregnated on kieselguhr and were sequentially eluted with 6N H2SO4+xN oxalic acid+H2O2(where x=0.1, 0.5 and 2). Similarly, in reversed phase paper chromatographic study in which a coating of HDEHP on Whatman No. 1 chromatographic paper was used as stationary phase, the mobile phase, 18N H2SO4+0.1N oxalic acid + H2O2, helped in separating the elements with favorable separation factors. Under the optimal conditions, the separation and decontamination of the elements in both methods were found to be quantitative, as verified by -spectrometric studies.
In this article we studied the dynamic dissociation constant (kd) of 99Mo complexed with insulin molecule at various pH. The kd values were determined by dialysis technique against deionised water. The T1/2 of the molybdenum–insulin complexes were found to be 6.41, 5.25 and 3.5 h at pH 5, 6 and 7 respectively. The half-lives indicate
that insulin may act as good carrier of 99Mo to the intestine and may be useful in the field of nuclear medicine.
The uptake behavior of long-lived radionuclides such as 134Cs (2.06 years), 137Cs (30 years) or 133Ba (10.54 years) on calcium alginate (CA) beads have been investigated. The CA beads are able to remove 133Ba (92%) at pH 7 after 90 min of exposure from the binary mixture of two. The separation method of short-lived daughter 137Ba (2.55 min) from its long-lived parent 137Cs (30 years) using this CA beads have also been developed.
No-carrier-added (nca) 208,209,210At was produced for the first time from 9Be induced reaction on thallium carbonate target at BARC-TIFR pelletron, Mumbai, India. The target of 4 mg/cm2 thickness was prepared by centrifugation technique. Nca At was separated from the thallium target by liquid–liquid extraction
using liquid cation exchanger HDEHP dissolved in cyclohexane and liquor ammonia.
Amongst various radionuclides of molybdenum, 90Mo and 99Mo have suitable β energy for clinical uses. In this paper we report separation of 99Mo from 99Mo-99mTc equilibrium mixture. The liquid–liquid extraction technique has been employed using trioctylamine (TOA) diluted in cyclohexane
as organic phase and HCl as aqueous phase. At 10−5 M HCl and 0.5 M TOA concentration 99mTc quantitatively transferred to the organic phase leaving 99Mo in the aqueous phase. The developed separation method is efficient and provides very high separation factor.
An aqueous biphasic extraction system was designed using different molecular weights of polyethylene glycol and concentrated
salt solutions of sodium sulphate to separate the heavy metals, Hg, Tl and Pb from Li irradiated Au matrix. All the four elements
could be separated from one another by this extraction process by simply optimizing the salt rich phase, the pH of the salt
rich phase and the molecular weight of the polymer rich phase.
Extraction behavior of zirconium and hafnium tracers,95Zr and175,181Hf, in HF, HCl, HNO3 and H2SO4 media with the liquid anion exchanger TOA has been studied. Under optimum conditions, TOA was found to be very effective for quantitative extraction of the individual elements at their trace scale concentrations, but due to higher extractibility and almost identical chemical behavior of the radiotracers towards TOA, the reagent was not so effective for mutual separation of the elements when they were present as congeneric pairs in the aqueous solutions. Extents of extraction of the elements at different stages were measured by -ray spectrometry.