Preparation of a new Cu(II)-imprinted polymer and its application for the determination of trace copper in water samples by flame atomic absorption spectrometry

Abstract

A new Cu(II)-imprinted polymer has been prepared for selective solid-phase extraction of Cu(II) prior to its determination by flame atomic absorption spectrometry. Two functional monomers, 4-(methacryloylamino)benzamide and 4-vinylpyridine, formed a complex with Cu(II) ion through coordination interactions. The self-assembled Cu(II)-monomer complex was copolymerised via bulk polymerisation method in the presence of ethyleneglycoldimethacrylate cross-linker. In order to remove Cu(II) ions, the resulting polymer was washed with 1.0 M HNO3 and then with water until obtaining a neutral pH. The ion imprinted polymer was characterised by Fourier transform infrared. The experimental conditions were optimised for solid-phase extraction of Cu(II) using a column of ion-imprinted polymer (IIP). Quantitative retention was achieved between pH 5.0 and 7.0, whereas the maximum recovery for the non-imprinted polymer (NIP) was about 74% at pH 7.0. The IIP showed higher selectivity to Cu(II) in comparison to the NIP. The IIP also exhibited excellent selectivity for Cu(II) in the presence of other metal ions. The relative standard deviation and limit of detection (3s) of the method were 1.6% and 1.8 µg L−1, respectively. The method was verified by analysis of two certified reference materials (CWW-TM-D and SRM 3280) and then applied to the determination of Cu(II) in seawater and lake water samples and haemodialysis concentrates.