Synthesis and Application of a Novel Poly(Acryl-p-Toluenesulfonamideamidine-p-Toluenesulfonylamide) Chelating Fiber for Preconcentration and Separation of Trace Noble Metal Ions from Solution Samples

A novel poly(acryl-p-toluenesulfonamideamidine-p-toluenesulfonylamide) chelating fiber containing S, N and O elements was synthesized from polyacrylonitrile fiber and p-toluenesulfonamide and used for the preconcentration and separation for traces of Ru(III), Rh(III), Au(III) and Pd(IV) ions from waste water and ore sample solution. The synthesis of this fiber was simple and rapid. The results indicate that 100 ng mL−1 of these ions can be quantitatively enriched by the chelating fiber at a flow rate of 6 mL min−1 and a pH of 4 and desorbed quantitatively with 20 mL of 6 mol L−1 HCl and 5% CS(NH2)2 solution at 50 °C (with recovery> 95%). A 50 to 1000-fold excess of Ca2+, Mg2+, Mn2+, Co2+, Fe3+, Cu2+, Zn2+, and Al3+ ions caused little interference in the concentration and determination of the analyzed ions. When the fiber had been reused twenty times, the recoveries of the ions enriched by the fiber were still over 96%. The saturated adsorption capacities of the fiber were in the range of 22–96 mg g−1. The relative standard deviation (RSD) of the method was between 0.70% and 0.84%. Recoveries of a standard added to actual samples were in range of 95–101%. The results obtained for these ions in real solution samples were basically in agreement with the given values, the average errors being below 5.0%. FT-IR spectra show that the existence of –SO2–Ar, HN=C–NH–, O=C–NH– and –NH–SO2 functional groups are verified in the chelating fiber. The experiments show that the method is rapid, precise, simple and convenient.