Abstract: A monolithic column of macro porous poly(glycidyl methacrylate-divinylbenzene) (poly(GMA-DVB)) has been prepared by free radical polymerization within the confines of a chromatographic stainless steel tube (50 mm×4.6 mm). For the best separation and low back pressure, orthogonal experiments were carried out with V(cyclohexanol): V(dodecanol), V(GMA): V(DVB) and BPO dosage as the three main factors. The characteristic feature of the column, including specific surface area, pore volume as well as pore diameter distribution, was studied by scanning electron microscopy (SEM), mercury intrusion porosimetry analysis and BET analysis. The obtained optimum preparation conditions were that the volume ratio of GMA, DVB, cyclohexanol and dodecanol was 0.825:0.825:1.32:2.03 and the BPO dosage was 0.7%(mass percentage), then it was heated at 70 ℃ for 24 h. Using this monolithic column, benzene and ethylbenzene and a drug of oxiracetam can be well separated on a high performance liquid chromatographic (HPLC) system equipped with a ultraviolet (UV) detector at 254 nm. A solution of acetonitrile-water (50:50, v/v) for the separation of benzene and ethylbenzene, and acetonitrile-water (80:20, v/v) for the separation of oxiracetam were used as mobile phases at a flow rate of 1 mL/min. The theoretical plate number was 37000 plates/m and the resolution of peak width at half height (R1/2) was 7.14. The separation time was less than 10 min. The monolithic column prepared by this method is reproducible and has high column efficiency. It is an economical method to prepare monolithic column, which can be applied to separate small molecules.

Key words: high performance liquid chromatography (HPLC), monolithic column, preparation, small molecular , poly(glycidyl methacrylate-divinylbenzene)