Monodisperse-porous beads with different polarities were prepared by "modified seeded polymerization". Poly(2-hydroxyethyl methacrylate-ethylene dimethacrylate), poly(HEMA-EDM), beads were the most polar structure obtained by the proposed method. A macromonomer, poly(ethylene glycol methacrylate) was first used for the synthesis of poly(polyethylene glycol methacrylate-ethylene dimethacrylate), poly(PEGMA-EDM), beads having relatively apolar structure with respect to poly(HEMA-EDM). A more apolar packing material, monodisperse poly(ethylene dimethacrylate), poly(EDM), beads, was also obtained by using only the crosslinking agent (i.e. ethylene dimethacrylate) as the monomer phase in the synthesis. The average pore size of poly(HEMA-EDM) beads was reasonably higher with respect to poly(PEGMA-EDM) and poly(EDM) beads. All bead types were slurry packed into the HPLC columns and their chromatographic performances were investigated by the isocratic separation of alkylbenzenes in the reversed phase mode. The chromatographic separation was achieved with the lower acetonitrile (AcN) concentration in the columns with higher polarity. More polar columns including poly(HEMA-EDM) or poly(PEGMA-EDM) beads provided higher column efficiency with low AcN concentration. Among the materials produced, the stationary medium including poly(EDM) beads gave the highest resolution power. Although the mobile phase flow rate was increased fourfold. the resolution power could be preserved with poly(HEMA-EDM) column. The results indicated that monodisperse particle based stationary media were obtained in a reasonably wide polarity range by the proposed protocol. (C) 2004 Elsevier B.V. All rights reserved.