Abstract
Amber lite XAD-4 resin (AXAD-4) has been functionalized by coupling it through an -N=N- group with 1-(2-pyridylazo)-2-naphthol (PAN). The resulting chelating resin, PAN-AXAD-4, has been characterized by using elemental and thermogravimetric analysis, infrared spectra, water regain value, and hydrogen ion capacity. The sorption capacity was found to be (285, 145, 135, 85, and 76) mu mol.g(-1) for Zn(II), Co(II), Ni(II), Cu(II), and Pb(II), respectively. The kinetics was studied at different temperatures, and the corresponding rate constants were also determined. All the metals could be eluted with 5 mL of HNO3 resulting in a high preconcentration factor of 300 to 500. The detection limits were found to be (0.65, 0.80, 0.85, 0.95, and 1.40) mu g.L-1 for Zn(II), Co(II), Ni(H), Cu(II), and Pb(H), respectively. The validity of the method was checked by analyzing standard reference materials and performing recovery studies. The analytical utility of the PAN-AXAD-4 for preconcentration and determination of metal ions was explored by analyzing river, canal, sewage, tap water, multivitamin formulation, and infant milk substitute by direct as well as the standard addition method.