Metal ion-imprinted polymethacrylate beads with sizes ranging from 100 to 300 mu m were prepared by suspension polymerization for the application of selective separation of target metal ions. The metal ion contacting area of the beads was enlarged via pore formation (BET 425 m(2)/g) using toluene as a porogenic agent. The synthesis of the copper-imprinted porous beads was verified using FTIR, SEM, and ESCA. Separation capacity and selectivity were investigated carrying out column separation experiments. The selective adsorption behavior of the imprinted beads was significantly affected by flow rate, pH, and metal ion concentration in the solution. Adsorption of the copper ion, the template metal ion, onto the beads was highly selective, compared with other ions such as nickel and zinc, with the selective coefficients at approximately 5-10. The microporous particles possessing such high selectivity has a potential application as novel column packing materials especially requiring high selective efficiency, which is usually not achievable by commercial ion exchange resins. (C) 2009 American Institute of Chemical Engineers AIChE J, 55: 3248-3254, 2009