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  • Author or Editor: Y. Maki x
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Abstract  

The separation and distribution of the chemical forms of131I produced from thermal neutron-irradiated tellurium compounds were investigated by thin-layer chromatography using alumina as adsorbent and water as developer as well as the effect of iodine carriers added on the distribution of different chemical forms of131I was studied. The effects of both atmospheric oxygen and light were investigated on the oxidation of carrier-free iodide on the thin-layer plate.

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Abstract  

77As(III) and77As(V) were separated from neutron-irradiated GeO2 by a thin-layer chromatographic method, in which silica gel was used as adsorbent and a 2∶1 mixture of methanol and 5N HCl as developer. The Rf values of these nuclides were as follows: 0.00 for77Ge, 0.50 for77As(III) and 0.94 for77As(V). The influence of As(III) carrier added before the separation was investigated on the oxidation state of77As recoiled from the parent nuclide. The radiochemical purity of77As thus separated was more than 99.9% and the activity due to77As could easily be eluted with water from the adsorbent, with 93% recovery.

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Abstract  

The separation of daughter nuclides in the carrier-free state from90Sr−90Y and140Ba−140La aqueous solution systems was performed by thin-layer chromatographic methods. (1) When a silica gel adsorbent and a developer of 1N NaCl, KCl, NH4Cl, CaCl2, SrCl2 or BaCl2 solutions was employed,90Y and140La were retained at the origin, while90Sr and140Ba advanced with the developer front. Addition of gypsum as binder to the silica gel prevented the separation of the140Ba−140La system, retaining both components at the origin. (2) When the140Ba−140La system was developed with water on a silica gel adsorbent containing 5% of gypsum, which was treated with various concentrations of nitric acid, the Rf value of140La increased with the concentration of nitric acid used, reaching a maximum of 0.98 at 0.1 N. The Rf value then decreased on the further increase of the concentration of nitric acid. When the same process was applied to the90Sr−90Y system, there was no separation. The radiochemical purities of90Y and140La obtained in the above two ways were more than 99%.

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Abstract  

A new α track method is proposed for the measurement of radon (222Rn) concentration in environmental levels. This involves collecting radon daughters on the surface of pilot lamp and detecting α-particles emitted from the nuclides (218Po and214Po) by a detector (LR 115). The detection sensitivity of this method is 6 times greater than that of the conventional α track method.

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Abstract  

An experimental method is described for the synthesis of195mPt-radiolabeled (–)-(R)-2-aminomethylpyrrolidine (1,1-cyclobutanedicarboxylato)-2-platinum (II) (DWA2114R). An amount of 10 mg of 95% enriched194Pt was irradiated for 75 h in the hydraulic conveyer of the KUR at a thermal neutron flux of approximately 8.1×1013 n.cm–2.sec–1 and the195mPt-radiolabeled DWA2114R was purified using HPLC. The chemical yield is higher than 65%, its chemical purity is greater than 99.2%, the radiochemical purity is nearly 100%, and the specific activity is 6.7 MBq. mg–1 DWA2114R.

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