Preparation of novel ion exchange polyurethane foam and its application for separation and determination of palladium in environmental samples.
The new strong anion exchanger (PUFIX) from polyurethane foam was prepared by coupling of the primary amine of the foam matrix with ethyl iodide. PUFIX was characterized using different tools (IR spectra, elemental analysis, density and thermal analysis). The sorption properties of the new anion exchanger (PUFIX) and chromatographic behaviour for separation and determination of palladium(II) ions at low concentrations from aqueous iodide or thiocyanate media were investigated by a batch and dynamic processes. The maximum sorption of Pd(II) was in the pH range of 0.3-2. The kinetics of sorption of the Pd(II) by the PUFIX was found to be fast with average values of half-life of sorption (t(1/2)) of 3.32 min. The variation of the sorption of Pd(II) with temperature gives average values of DeltaH, DeltaS, DeltaG and DeltaE to be -38.3 kJ mol(-1), -100.7J K(-1) mol(-1), -8.3 and 11.8 kJ mol(-1), respectively. The sorption capacity of PUFIX was 1.69 mmol g(-1) for Pd(II), preconcentration factors of values approximately 250 and the recovery 99-100% were achieved (R.S.D. approximately 1.24%). The lower detection limit, 1.28 ng mL(-1) was evaluated using spectrophotometric method (R.S.D. approximately 2.46%).
Moawed
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Chemistry Department, Faculty of Science at Damietta, Mansoura University, Egypt. eamoawed@yahoo.com