In order to assess radiation dose due to radioiodine released to the environment from nuclear facilities, it is necessary to estimate the amount of the nuclide in edible parts of crops through various pathways. In this paper, uptake of the iodine from the surface of crops through a wet deposition pathway was investigated by radio-tracer experiments. Plants studied were Komatsuna, a green leafy vegetable, and rice plant. The pathway selected is expected to be an important one in the natural environment. Translocation of the nuclide within the plants was also studied. Results obtained were as follows: (1) Iodide was taken up by Komatsuna leaf more readily than iodate. (2) More than 95% of the iodide taken up from unhulled rice remained in the hull. This suggested that hardly any iodide translocated from the hull to brown rice. (3) Iodide content in brown rice after a 1 hour exposure experiment was a bit more than that after a 0.5 hour exposure test. (4) Hardly any iodine seemed to translocate from the contaminated part to other parts in either Komatsuna or rice plants.
A capillary gas chromatography-mass spectrometry for analysis of15N-labeled amino acids and amides is described. The method is based on direct silylation of amino acidsand amides with MTBSTFA and the formation of the TBDMS derivatives. The method was possible simultaneously to measure the15N abundance ratio of amino-N and amide-N of amides, as to analysis of amino acids.
127I Mössbauer spectra of good quality were obtained at 20 K using a Zn127mTe source produced by high flux neutron irradiation of66Zn-126Te at reactor core. The Mössbauer spectra for KI and some iodine (III) compounds with absorption intensity of about 5 % suggest that the127I Mössbauer spectroscopy is useful in elucidating the bonding nature of the iodine compounds. Preparative method of the Mössbauer source and experimental technique are reported in detail.
An accurate and rapid radiochemical method has been developed for the determination of microgram amount of silver employing potassium ethyl xanthate as a Substoichiometric radiochemical reagent. The light yellow coloured silver ethyl xanthate formed was extracted into nitrobenzene from sulphuric acid media. The effect of foreign ions on the extraction was studied. The method was applied to the determination of silver content in photofilm washings.
A radiochemical method has been developed for the determination of microgram amounts of cadmium based on the substoichiometric extraction of its 1: 2 complex with potassium ethyl xanthate into 1: 4 v/v mixture of pyridine and ethyl acetate from 2.5M sodium formate. 10-90μg of cadmium was determined with an average error of ±1.96%. The method developed was successfully applied to the determination of Cd contents in water samples.
The purpose of this study is to assess the dentifrice abrasivity of both commercially available products and test products. The assessment of abrasivity was carried out by the measurrnent of32P released from tooth by using radioactive dentifrice abrasion (RDA) method. In dentine, RDA values, which show the polishing ability for dentine, were 65-100 with dentifrices with normal cleaning power and 106-182 with those with high cleaning power, respectively. On the other hand, REA values which show the polishing ability for enamel were 12-405 with both market products and test products. The difference of the REA values according to the dentrif rices appears to be largely influenced by the difference of polishing agents of each dentifrice. It is concluded that RDA method is usef ull for assessing of dentifrice abrasivity. However, particular attention should be given to the abrasion of dentine.