Hexyl methacrylate-based monolithic columns prepared by radiation-induced polymerization

Ueki, Yuji; Umemura, Tomonari*; Iwashita, Yoshikazu*; Hotta, Hiroki*; Odake, Tamao*; Tsunoda, Kinichi*; Katakai, Akio; Tamada, Masao

In late years, the studies on monolithic columns, which consist of porous material with through-pore of a few micrometer dimensions, have been vigorously performed for rapid and high-resolution separations. Monolithic capillary columns for reversed-phase liquid chromatography were directly prepared by ray-induced polymerization of hexyl methacrylate (HMA) and ethylene dimethacrylate in the fused silica capillaries, 0.25 mm in inner diameter. High separation efficiency of the monolithic columns were realized when the columns were prepared in the condition of 10 kGy irradaiation, total monomer concentration of 20% inclusive 25% crosslinker. The produced HMA-based monolithic columns were composed of adhered polymer particles, 1 m and less than in diameter. The pressure drop of column, this 200 mm long, was below 2.0 MPa at linear velocity of 1 mm s. The height equivalent to a theoretical plate was approximately 30 m for the five kinds of alkylbenzenes.