chelation
  螯合作用
  che·la·tion /kɪˈleʃən/ 名詞
  螯合作用
  chelation
       n 1: (medicine) the process of removing a heavy metal from the
            bloodstream by means of a chelate as in treating lead or
            mercury poisoning
       2: the process of forming a ring by forming one or more
          hydrogen bonds