Available online at www.sciencedirect.com Journal of Hazardous Materials 158 (2008) 131–136 A solid phase extraction procedure for Fe 3+ , Cu 2+ and Zn 2+ ions on 2-phenyl-1H-benzo[d] imidazole loaded on Triton X-100-coated polyvinyl chloride Mehrorang Ghaedi a,∗ , Khodabakhsh Niknam b , Ardeshir Shokrollahi a , Ebrahim Niknam b , Hamed Ghaedi a , Mustafa Soylak c a Chemistry Department, Yasouj University, Yasouj 75914-353, Iran b Chemistry Department, Persian Gulf University, Bushehr, Iran c Chemistry Department, University of Erciyes, 38039 Kayseri, Turkey Received 29 November 2007; received in revised form 13 January 2008; accepted 14 January 2008 Available online 19 January 2008 Abstract A new and efficient solid phase extraction method is described for the preconcentration of trace heavy metal ions. The method is based on the adsorption of Fe 3+ , Cu 2+ and Zn 2+ on 2-phenyl-1H-benzo[d] imidazole (PHBI) loaded on Triton X-100-coated polyvinyl chloride (PVC). The influences of the analytical parameters including pH and sample volume were investigated. Common coexisting ions did not interfere on the separation and determination of analytes under study. The adsorbed analytes were desorbed by using 5 mL of 4 mol L -1 nitric acid. The preconcentration factor is 90. The detection limits (3 sigma) were in the range of 0.95–1 gL -1 . The sorbent exhibited excellent stability and its sorption capacity under optimum conditions has been found to be more than 2.7 mg of ions per gram of sorbent. The recoveries of analytes were generally higher than 95%. The relative standard deviations (R.S.D.s) were generally lower than 4%. The method has been successfully applied to some real samples. © 2008 Elsevier B.V. All rights reserved. Keywords: Surfactant-coated polyvinyl chloride; Trace metal; Atomic absorption spectrometry; Solid phase extraction 1. Introduction The considerable emphasis has been carried out on the removal of toxic metal ions, lead to the development of a variety of analytical methodologies. Hence, there has been considerable growth in the analytical chemistry of various metal ions [1–4]. Accurate and precise analyses of traces of heavy metal ions by instrumental analysis techniques including inductively cou- pled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and flame atomic absorption spectrometry (FAAS), etc. are an important part of the analytical chemistry [5–7], because of ecological and health problems associated with environmental contami- nation continues to rise. Direct instrumental analysis of these samples is difficult because of complex formation and signifi- ∗ Corresponding author. Tel.: +98 741 2223048; fax: +98 741 2223048. E-mail address: m ghaedi@mail.yu.ac.ir (M. Ghaedi). cant matrices, which invariably influence normal instrumental analysis [8]. In addition, some metals have low concentrations, which are near or below the limit of detection of the instrument. Preconcentration can solve the above two problems and leads to simplified heavy metal determination [9–14]. Solid phase extraction is a universal technique in this respect compared to the conventional liquid extraction [15–18]. Solid phase extraction is based on the utilization of a major constituent as bonded station- ary phase immobilized with different ligand or functional group. The nature of the functional group determines the phase selec- tivity for metal ion while the regeneration of the phase depends on polymer matrix [15–19]. PVC-coated analytical reagent possesses some definite advantages [20]. It does not swell or strain, has good mechani- cal strength and undergoes heat treatment. Suitable applications of modified PVC for the separation and preconcentration of metal ions from large sample volume demand the process to be both thermodynamically and kinetically favorable. To achieve maximum efficiency it is necessary to optimize the operational 0304-3894/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.jhazmat.2008.01.037