Abstract: Three new chelating resins (PTAP- Ⅰ, PTAP- Ⅱ and PTAP- Ⅲ ) with a polythioether backbone bearing pyridylamino groups are first synthesized by the amination of poly-chloromethylthiirane with various aminopyridine (i. e. 2-aminopyridine, 3-aminopyridine and 4-aminopyridine) by using diethylenetriamine as the crosslinking agent. These resins cheJate strongly with Ag( Ⅰ ), Au( Ⅲ ) and Pd( Ⅱ ), moderately with Pt(Ⅳ), Hg( Ⅱ ) and Cu( Ⅱ ), as well as weakly with Zn( Ⅱ ) and Cd( Ⅱ ), whereas Pb( Ⅱ ) could not be chelated. PTAPresins possess excellent selectivity for noble metal ions. Au(3) or Pd( Ⅱ ) is only adsorbed from the solution of salts including Au( Ⅲ ) or Pd( Ⅱ ), Zn( Ⅱ ), Hg( Ⅱ ) and Cd( Ⅱ ) etc. In addition, from the mixed solution of PdCl₂ and H₂PtCl₆ Palladium( Ⅱ ) is adsorbed, but platinum(Ⅳ ) can hardly be adsorbed. The influence of acidity of medium on adsorption efficiency of PTAP for Au( Ⅲ ), Pd( Ⅱ ), Pt( Ⅳ ) is also investigated.

Key words: Chelating resins, Polychloromethylthiirane, Aminopyridine, Noble metals, X-ray photo- electric spectrometry