The effect of solvent/monomer (S/M) feed ratio on the structure and adsorption properties of copper(II)-imprinted microporous polymer particles was investigated. Copper(II) ion-imprinted microporous particles were prepared from two functional monomers, methacrylic acid (MAA) and vinyl pyridine (4-VP), by forming a complex with the template copper ion by ionic interactions. The self-assembled copper/monomer complex was polymerized in the presence of an ethylene glycol dimethacrylate (EGDMA) cross-linker by a suspension polymerization. The diameter of the prepared microparticles was 200-700 mu m. The chemical structure, morphology and adsorption capacity of the Cu(II)-imprinted microporous particles were analyzed using scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) test, atomic adsorption spectroscopy (AAS), furrier transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectrometer (EDX). The adsorption capacity of the imprinted beads for the template ion, Cu(II), was significantly affected by the initial concentration and pH of the feed solution. The imprinted particles showed high selectivity for the copper ion, as the adsorption capacity for the Cu(II) ion was much higher than that of other metal ions such as Ni(II), Zn(II), and Cd(II). The adsorption capacity, adsorption kinetics, and selectivity of the imprinted particles prepared in this study, however, were not significantly affected by the S/M feed ratio. (C) 2010 Elsevier B.V. All rights reserved.