A new functionalized resin and its application in flame atomic absorption spectrophotometric determination of trace amounts of heavy metal ions after solid phase extraction in water samples

In this work, Amberlite XAD-4 functionalized with salicylic acid through an azo linkage (-N=N-) was synthesized and used as a new chelating resin for preconcentration of Pb(II), Cu(II), Ni(II), Co(II), and Zn(II) in water samples. The resin was characterized by scanning electron microscopy, elemental analysis. Fourier transform infrared spectroscopy, and thermogravimetric analysis. Determination of the metal ions was carried out by flame atomic absorption spectrophotometry. Metal ion sorption equilibria were reached within 30 min. The preconcentraion factor was 50 for a 500 mL sample. The sorbed metal ions were eluted by 10 mL of 0.5 M HNO3 within 10 min with the desorption recovery of >= 90%. This new method gave a good accuracy in batch system as indicated by the recovery of >= 93% for the extraction of all metal ions and R.S.D. less than 1.4% (n=5). The detection limits for Pb(II), Cu(II), Ni(II), Co(II) and Zn(II) were 0.15, 0.18, 0.18, 0.21, and 0.19 respectively. (C) 2012 Elsevier B.V. All rights reserved.