Nakazawa Emiko, Ikemoto Tokutaka, Hokura Akiko, Terada Yasuko, Kunito Takashi, Yamamoto Takahito, Yamada Tadasu K, Rosas Fernando C W, Fillmann Gilberto, Tanabe Shinsuke, Nakai Izumi
Department of Applied Chemistry, Tokyo University of Science, Kagurazaka 1-3, Shinjuku-ku, Tokyo, 162-8601, Japan.
J Environ Monit. 2011 Jun;13(6):1678-86. doi: 10.1039/c1em10115c. Epub 2011 Apr 14.
The chemical form of Ag in the livers of five species of marine mammals was examined using X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies. The XAFS analysis suggested that Ag(2)Se was present in the livers of the Franciscana dolphin (Pontoporia blainvillei), Dall's porpoise (Phocoenoides dalli), and Baird's beaked whale (Berardius bairdii), whereas Ag(2)S was present in the livers of the striped dolphin (Stenella coeruleoalba) and pygmy killer whale (Feresa attenuata). XRF spectroscopy results revealed that the distribution patterns of Ag and Se in a thin section of the liver of the Franciscana dolphin were the same; this also implied that Ag was associated with Se in the liver. Thus, the interaction of Ag with Se or S may offer significant protection against the toxicity of Ag in marine mammals. The formation of either Ag(2)Se or Ag(2)S might depend on the Hg levels in the liver. Ag(2)Se was observed in liver samples with relatively high Ag/Hg ratio, whereas liver samples with low Ag/Hg ratio contained Ag(2)S.
利用X射线吸收精细结构（XAFS）和X射线荧光（XRF）光谱技术，对五种海洋哺乳动物肝脏中银的化学形态进行了检测。XAFS分析表明，在弗氏海豚（Pontoporia blainvillei）、白腰鼠海豚（Phocoenoides dalli）和贝氏喙鲸（Berardius bairdii）的肝脏中存在Ag(2)Se，而在条纹海豚（Stenella coeruleoalba）和侏虎鲸（Feresa attenuata）的肝脏中存在Ag(2)S。XRF光谱分析结果显示，弗氏海豚肝脏薄片中银和硒的分布模式相同；这也表明肝脏中的银与硒有关联。因此，银与硒或硫的相互作用可能为海洋哺乳动物提供重要的保护，使其免受银的毒性影响。Ag(2)Se或Ag(2)S的形成可能取决于肝脏中的汞含量。在银/汞比值相对较高的肝脏样本中观察到了Ag(2)Se，而银/汞比值较低的肝脏样本中含有Ag(2)S。
