Kamalika Roy

Synthesis of a new ion exchanger, zirconium vanadate, and its application to the separation of barium and cesium radionuclides at tracer levels.

A new inorganic ion exchanger, zirconium vanadate, has been synthesized and characterized. Elemental analysis suggests that the probable formula of the compound is ZrO2, V2O5, 2H2O. The exchanger is highly stable in thermal, radiation and chemical environments. Radiochemical separation schemes for the 134Cs and 133Ba pair and also for separating the short-lived daughter 137Ba from its parent 137Cs using this newly synthesized ion exchanger have been developed.

In Situ γ-Radiation: One-Step Environmentally Benign Method To Produce Gold−Palladium Bimetallic Nanoparticles

Synthesis of gold-palladium bimetallic nanoparticles using in situ radioactivity from (198)Au isotope is reported in this paper. Gold solution spiked with (198)Au(III) has been mixed with PdCl2 solution in measured proportions in 50% polyethylene glycol solution. Au(III) and Pd(II) are reduced, and nanoparticles are formed due to radiolysis of the polymer solution. The solution has been characterized by UV-visible spectra, and the actual size has been determined using transmission electron microscopy in conjugation with energy dispersive X-ray measurements.

Species dependent radiotracer study of Cr(VI) and Cr(III) using an aqueous biphasic system

The speciation study of Cr(III) and Cr(VI) was carried out using a polyethylene glycol (PEG) based aqueous biphasic extraction system (ABS). Neutron activated Cr(III) and Cr(VI) salts were assayed in a HPGe detector before and after employing aqueous biphasic extraction. Different salts of various salting out abilities were taken as the salt rich phase. The best condition for extraction of Cr(VI) and the maximum differential attitude of ABS to Cr(VI) and Cr(III) was observed when 2 M Na2SO4 and PEG #4000 (50% w/w) solutions were used. Cr(III) can also be extracted by the PEG with prior complexation with diphenylthiocarbazone (dithizone). The chromium dithizonate complex is quantitatively extracted by the PEG rich phase.

Extraction of long-lived radionuclides 152,154Eu and 134Cs using environmentally benign aqueous biphasic system

Abstract A polyethylene glycol based aqueous biphasic system has been studied for the extraction and separation of long-lived radionuclides, 152,154Eu and 134Cs. The effects of pH variation of the salt rich phases on the extraction properties of these radionuclides were studied and the experimental results were found to be supported by theoretical calculations. It has been observed that at neutral pH of sodium sulphite and at pH 11 of sodium phosphate salt rich phase 134Cs could be separated from 152,154Eu radionuclides. The exact phase forming concentrations of the salt rich phases were determined by measuring the volume of salt rich phase after equilibration.

Radiochemical separation of carrier-free 204,206Bi from α-irradiated thallium oxide target

Abstract Alpha activation of Tl 2 O 3 target results in the formation of carrier-free 204,206 Bi. Two different radiochemical methods were used for the separation of bismuth radionuclides from the target matrix. A very high separation factor was achieved using liquid–liquid extraction (LLX) method with methyl isobutyl ketone (MIBK)-HCl system. Solid–liquid exchange adsorption was carried out using a novel inorganic ion exchanger, zirconium vanadate from HCl medium. The separation was found to be maximum around pH 2.

Separation of carrier-free 95Tc from alpha-irradiated natural niobium

Abstract95Tc has been produced through α-particle activation of a natural niobium target. The carrier-free 95Tc radionuclide has been separated from the bulk target using tri-n-octylamine (TOA) diluted by cyclohexane as extracting agent and HCl, HNO3 as aqueous phase. Solid-liquid extraction has also been carried out with TOA impregnated Kieselguhr mineral acid system. Technetium-95 was recovered from the organic phase by stripping with 0.1M EDTA above pH 9.