放射光蛍光X線分析を用いるヒ素高集積植物モエジマシダの根におけるヒ素の分布及び化学形態分析  [in Japanese] Distribution and Oxidation State of Arsenic in Root of Arsenic-Hyperaccumulator Fern, Pteris vittata L., by Using Synchrotron Radiation X-Ray Fluorescence Analysis  [in Japanese]

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Abstract

モエジマシダ(<i>Pteris vittata</i> L.)は,ヒ素を高濃度に蓄積する能力をもつことから,実際にファイトレメディエーションへ応用されつつある植物である.このモエジマシダの根に放射光蛍光X線分析を適用することで,伸長方向に沿ったヒ素の分布と価数を初めて明らかにした.試料の前処理として凍結乾燥を施すことで,X線分析におけるハンドリングを容易にし,測定では縦300 μmと垂直方向に集光する一方で,横2800 μmと水平方向に大きなビームを照射した.以上により,根のうねりや形状の影響を排除して根の伸長方向における元素分布と複数の元素の相関を評価することが可能となった.その結果,根の先端から基部に向かって,カリウムの濃度はほぼ一定であるのに対し,ヒ素の濃度は相対的に高くなることが明らかとなった.またヒ素の価数は,先端では3価の存在が支配的であったが,基部に向かうと次第に5価が支配的になることが分かった.<br>

<i>Pteris vittata</i> L. has come into use as a technology of phytoremediation due to its hyperaccumulation ability of As. The distributions of arsenic and potassium in roots were examined by synchrotron radiation (SR)-XRF imaging; and the valence change from the top to the base of roots was revealed for the first time by As K-edge XANES. Freeze-drying technique was adopted as an effective preparation method for the handling of roots. The vertical beam size was set to 300 μm by a spherical focusing mirror and the horizontal beam size was adjusted to 2800 μm by the slits. By adopting this wide X-ray beam, the elemental distribution along the roots can be appropriately evaluated despite their winding shapes. It was found that the concentration of arsenic became higher from the top to the base of the roots, while that of potassium remained almost constant. Furthermore, the oxidation state of arsenic at the top of the roots was dominantly As(III), while that at the base was As(V).<br>

Journal

  • BUNSEKI KAGAKU

    BUNSEKI KAGAKU 55(10), 743-748, 2006-10-05

    The Japan Society for Analytical Chemistry

References:  12

Cited by:  1

Codes

  • NII Article ID (NAID)
    110004823097
  • NII NACSIS-CAT ID (NCID)
    AN00222633
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    05251931
  • NDL Article ID
    8541003
  • NDL Source Classification
    ZP4(科学技術--化学・化学工業--分析化学)
  • NDL Call No.
    Z17-9
  • Data Source
    CJP  CJPref  NDL  NII-ELS  J-STAGE  NDL-Digital 
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