Application of chelate forming resin Amberlite XAD-2-o-vanillinthiosemicarbazone to the separation and preconcentration of copper(II), zinc(II) and lead(II)

A very stable chelating resin matrix was synthesized by covalently linking o-vanillinthiosemicarbazone (oVTSC) with the benzene ring of the polystyrene-divinylbenzene resin Amberlite XAD-2 through a -NN- group. The resin was used successfully for the separation and preconcentration of copper(II), zinc(II) and lead(II) prior to their determination by atomic absorption spectrophotometry. The total sorption capacity of the resin was 850, 1500 and 2000 mug g(-1) of the resin for Cu(II), Zn(II) and Pb(II), respectively. For the quantitative sorption and recovery of Cu(II), Zn(II) and Pb(II), the optimum pH and eluants were pH 2.5-4.0 and 4 M HCl or 2 M HNO(3) for Cu(II), pH 5.5-6.5 and 1.0-2.0 M HCl for Zn(II) and pH 6.0-7.5 and 3 M HCl or 1 M HNO(3) for Pb(II). Both, the uptake and stripping of these metal ions were fairly rapid, indicating a better accessibility of the chelating sites. The t (1 2 ) values for Cu(II), Zn(II) and Pb(II) were also determined. Limit of tolerance of some electrolytes like NaCl, NaF, NaNO(3), Na(2)SO(4) and Na(3)PO(4) have been reported. The preconcentration factor for Cu(II), Zn(II) and Pb(II) was 90, 140 and 100 respectively. The method was applied for the determination of Cu(II), Zn(II) and Pb(II) in the water samples collected from Sabarmati river, Ahmedabad, India.