In this article we described our new approach to the polymer monolith with its morphology tailored for HPLC application to small solutes such as drug candidates. We prepared polymer monoliths based on glycerin 1,3-dimethacrylate, GDMA with a bicontinuous structure by in situ photoinitiated free radical polymerization (UV irradiation at 365 nm). Our photopolymerization was carried out with a monodispese ultra high molecular weight polystyrene solution in chlorobenzene uniquely formulated as a porogen. The poly-GDMA monoliths in bulk, rod and capillary thus prepared showed a bicontinuous network-like structure featured by their fine skeletal thickness nearly in sub mu m size. This monolithic structure was considered as a time-evolved morphology frozen by UV-irradiation via viscoelastic phase separation induced by the said porogenic polystyrene solution. According to our mu HPLC measurement with acetophenone as a model solute, the UV prepared poly-GDMA capillary demonstrated a much shaper elution profile affording higher column efficiency and permeability as compared with the thermally prepared capillary of the same bore size. Our investigation showed experimentally that poly-GDMA monoliths with a well-defined bicontinuous structure could be prepared reproducibly by photoinitiated radical polymerization via viscoelastic phase separation using the said unique porogen. (C) 2008 Wiley Periodicals, Inc.