Copper was preconcentrated from aqueous solutions by adsorption on polymethyl methacrylate, polymethacrylonitrile, and their copolymers prepared by group transfer polymerization. Atomic absorption spectrometry was used to determine the metal ion. The copper (II) ion was collected from aqueous solutions starting from pH 2. In both homopolymers and copolymers, an increase of retention starting from pH 2 to 7 was observed. Below pH 2, no retention was observed. The retention of the ion from the aqueous phase on the polymers was above 90% at pH 7. (C) 1996 John Wiley & Sons, Inc.