Selective solid-phase extraction of trace copper ions in aqueous solution with a Cu(II)-imprinted interpenetrating polymer network gel prepared by ionic imprinted polymer (IIP) technique

An Cu(II)-imprinted interpenetrating polymer network (IPN) gel of epoxy-diethylenetriamine and methacrylic acid-acrylamide-N,N'-methylene-bis-(acrylamide) was synthesized by the ionic imprint polymer (IIP) technique. The first polymer network is formed by epoxy gelation with diethylenetriamine. The other is formed by copper methacrylate copolymerization with acrylamide and cross-linker N,N'-methylene-bis-(acrylamide). The adsorption-desorption characteristics of the IPN gel as a highly selective solid-phase extraction (SPE) and preconcentration adsorbent for Cu2+ from aqueous solution were investigated. The experimental results show that trace Cu2+ ions can be quantitatively enriched at pH 5 with recovery > 95%. The maximum static adsorption capacity of the ion-imprinted functionalized gel adsorbent was 76 mg g(-1). Comparing with non-imprinted IPN gel, the imprinted IPN gel has higher adsorption capacity and selectivity for Cu2+ by the static adsorption desorption experiment. Simultaneously, the times of adsorption equilibration and complete desorption were remarkably short. The precision (RSD) for 11 replicate adsorbent extractions of 20 ng mL(-1) Cu2+ was 3.4%. The established procedure was applied to two real water samples with satisfactory results. The prepared ion-imprinted IPN gel adsorbent was shown to be promising for solid-phase extraction coupled with atomic absorption spectrometry (AAS) for the determination of trace copper in real samples. In addition, the coordination interaction of Cu2+ and functional groups of the IPN gel adsorbent was primarily discussed by FT-IR spectra.