| Budget Amount *help |
¥5,600,000 (Direct Cost: ¥5,600,000)
Fiscal Year 1987: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1986: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Research Abstract |
1. The accuracy and precision of the neutron-activation analysis applied to plant samples were examined with standard samples of three kinds of plants. Satisfactory results were obtained for the determination of Na, K, Rb, Ca, Cr, Mn, Fe, Co, Zn, As, and Sb. By using this method, transition elements (Mn, Fe< Co, Zn, etc.), alkali metals (Na, K, Rb, and Cs), and some lanthnoid elements contained in pine ne edles and pepperbush leaves were determined. The results show that the content of each element differs bet ween the two plants growing at the same place and that pepperbush leaves universally concentrate Co independently of its growing place.
2. An apparatus for atomic absorption spectroscopic analysis was set up, and its sensitivity was determined with samples containing known amounts of metallic elements: results for Cr, Mn, Fe, Co, Zn, etc. were found to be satisfactory for present purposes. However, the direct method, according to which ashed plant samples were dissolved in acid and directly used for spectroscopic measurements, did not give quite satisfactory results with pine needles, except for Mn and K, the concentrations of which are relatively high. Preliminary chemical treatment for the elimination of interference is necessary for an accurate determination. The atomic absorption spectroscopy was also found to be useful for the determination of Ba contaminating Sr.
3. In order to solve basic problems for applying EXAFS and XANES method to samples from living matter, X-ray absorption spectroscopic studies were carried out with several crystalline compounds, samples of a few solution systems, and Ni-zeolite catalysts. Then the technique was applied to the investigation of the state of copper contained in nitrite reductase and ascorbate oxidase.
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