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Summary  

We report here a facile synthesis of [1-14C]-mandelic acid. Benzyl bromide on cyanation with K14CN followed by acid hydrolysis in a microwave oven gave [1-14C] phenylacetic acid. The latter on a-bromination followed by hydrolysis under microwave irradiation for 2 minutes furnished the title compound.

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Abstract  

High-level liquid waste from fast reactor fuel reprocessing stream contains significant quantities of lanthanides and trivalent minor actinides. The lanthanides and minor actinides (MA) have been separated from the fast reactor high-level liquid waste (FR-HLLW) using TRUEX solvent, which is a mixture of 0.2 M octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO)-1.2 M tri-n-butylphosphate (TBP) in n-dodecane. A new stripping composition, 0.1 M HNO3 and 0.1 M citric acid (CA), has been employed for back extraction of them from the TRUEX solvent. In order to separate lanthanides from actinides present in the strip solution, the extraction behavior of 241Am(III) and (152+154)Eu(III) from CA–HNO3 medium by a solution of bis-2-ethylhexylphosphoric acid (HDEHP) in n-dodecane has been studied. Separation factors (SF = D Eu/D Am) has been reported as a function of various parameters such as pH, concentrations of HDEHP, diethylenetriamine-N,N,N′,N′′,N′′′-pentaaceticacid (DTPA), 1-octanol and TBP in this paper.

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Abstract  

Prediction of downwind tritium air concentrations in the environment around Narora Atomic Power Station was studied on the basis of Gaussian plume dispersion model. The tritium air concentrations by field measurement [measured tritium air concentrations in the areas adjacent to NAPS] were compared with the theoretically calculated values (predicted) to validate the model. This approach will be useful in evaluating environmental radiological impacts due to standard pressurised heavy water reactors.

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The objective of this study was to develop and validate a novel, simple, and selective high-performance liquid chromatographic (HPLC) method with photodiode array detector for the estimation of tenofovir in rat plasma, which can be utilized in analyzing the pharmacokinetic samples from rats. Prior to analysis, an optimized protein precipitation technique was used to extract tenofovir from plasma. The mobile phase for this method comprised of 10 mM ammonium acetate buffer (pH 4) and methanol in the ratio of 97:3 υ/υ. Chromatographic separation of tenofovir was achieved using Spincotech C-18G enabled column (250 × 4.6 mm, 5 μm). Tenofovir was monitored at a wavelength of 260 nm, and the calibration curve was linear in the range of 250–4000 ng mL−1 (R 2 = 0.999). High recovery obtained after extraction (97%–101%) of plasma samples precluded the use of an internal standard. Validation studies were performed as per the standard guidelines, and the developed method was accurate, precise, and selective for the determination of tenofovir in the rat plasma. The stability studies performed during the sample pretreatment process and sample storage conditions did not show a quantifiable degradation of tenofovir. Further, this method was able to estimate tenofovir and determine its pharmacokinetic parameters, post IV bolus administration in male Wistar rats. The pharmacokinetic profile of tenofovir followed one compartmental open model.

Open access
Journal of Radioanalytical and Nuclear Chemistry
Authors:
P. Geetha
,
N. Karunakara
,
Ujwal Prabhu
,
P. Ravi
,
J. Sudhakar
,
Nicy Ajith
,
K. Swain
,
R. Acharya
, and
A. Reddy

Abstract  

Instrumental and preconcentration methods of neutron activation analysis (NAA) have been standardized for the determination of concentration of iodine in grass and cow milk samples, respectively. To study the transfer of iodine from grass to milk, known quantity of grass spiked with potassium iodide solution was fed to a cow. The spiked grass samples and milk samples, obtained from the cow after the ingestion of spiked grass, were collected. Iodine was separated from the milk samples chemically using Dowex 1X8 anion exchange resin. Spiked grass and ion exchange resin samples were neutron irradiated and radioactive assay was carried out using a 45 % relative efficiency HPGe detector coupled to an 8k channel analyzer. Iodine concentrations in spiked grass samples were found to be in the range of 1,487–2,002 mg kg−1. Concentration of iodine in milk after 12 h of feeding the cow with spiked grass was 871 ± 56 μg L−1 which was reduced to 334 ± 32 μg L−1 after 48 h.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Ravi
,
A. Deepa
,
B. Surekha
,
S. Susheela
,
P. Achuthan
,
S. Anil Kumar
,
K. Vijayan
,
U. Jambunathan
,
S. Munshi
, and
P. Dey

Abstract  

90Sr estimation in reprocessed uranium was carried out by a series of solvent extraction and carrier precipitation techniques using strontium and lanthanum carriers. Fuming with HClO4 was used to remove 106Ru as RuO4. Three step solvent extraction with 50% tri-n-butyl phosphate in xylene in presence of small amounts of dibutyl phosphate and thenoyl trifluoro acetone was carried out to eliminate uranium, plutonium, thorium and protactinium impurities. Lanthanum oxalate precipitation in acid medium was employed to scavenge the remaining multivalent ions. Strontium was precipitated as strontium oxalate in alkaline pH and 137 Cs was removed by washing the precipitate with water. A strontium recovery well above 70% was obtained. Final estimation was carried out by radiometry using end window GM counter after drying the precipitate under an infra red lamp. The same procedure was extended to the estimation of 90Sr in a diluted sample of the actual spent fuel solution. An additional lanthanum oxalate precipitation step was required to remove the entire 144Ce impurity from this sample. This modified procedure was employed in the determination of 90Sr in a number of reprocessed uranium samples and the over all precision of the method was found to be well within ±10%. An additional barium chromate precipitation step was necessary for the analysis of reprocessed uranium samples from high bumup fuels to eliminate trace amounts of short lived 224Ra produced during the decay of 232U and its daughters as they interfere in the estimation of 90Sr.

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Summary  

The activity and absorbed dose rate of the naturally occurring radionuclides, viz. 238U, 232 Th and 40K were determined in soil and rock samples collected around Kaiga site. The mean activity levels (Kaiga soil) of naturally occurring 232 Th are comparable with that in worldwide soil, while concentrations of 238U and 40K are lower than those in worldwide soil. The absorbed dose rate in outdoor air ranged 20-58 nGy . h-1 with a mean of 33.3 nGy . h-1, which is below the world average of 60 nGy . h-1. The total effective dose rate in outdoor air for soils ranged 25.6-74.4 mSv . y-1 with a mean of 43.0 mSv . y-1. The estimated dose rate at Kaiga is comparable with that estimated at Kakrapar and Rawatbhata and much less than that estimated at coastal sites of India.

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