Preparation and application of poly(2-amino thiophenol)/MWCNTs nanocomposite for adsorption and separation of cadmium and lead ions via solid phase extraction

A new method which utilizes a multiwalled carbon nanotubes/poly(2-amino thiophenol) nanocomposites as an effective sorbents in solid-phase extraction has been developed for separation and preconcentration of Cd(II) and Pb(II) trace levels in environmental samples. The method is based on the adsorption of heavy metals on macromolecular chains due to sharing an electron pair of =N- and -S- groups of conducting polymer with cadmium and lead ions. The results indicate the novel nanocomposite presents a high affinity for heavy metals due to the presence of several good extractive sites (S and N) which are introduced to the synthesized nanocomposite. Some parameters including sample condition such as: pH, flow rate, sample volume, and eluent condition such as: type, volume, and concentration: moreover adsorption capacity of matrix ions was investigated on the recovery of Cd(II) and Pb(II). The maximum adsorption capacity of MWCNTs/P2AT nanocomposite as sorbents at optimum conditions for cadmium and lead ions was found to be 178.7 mg g(-1) and 186.4 mg g(-1), respectively. The detection limits of this method were 0.3 and 1 ng mL(-1) for Cd(II) and Pb(II), respectively. The validation of the presented procedure was checked by reference material analysis. Finally, the presented procedure was applied for determination of Cd(II) and Pb(II) in some environmental samples. (C) 2011 Elsevier B.V. All rights reserved.