Octadecylsilylated porous silica rods as separation media for reversed-phase liquid chromatography

Continuous porous silica rods consisting of a mesoporous (pore size, 14 or 25 nm) silica skeleton of similar to 1 mu m size and through-pores of similar to 1.7 mu m were prepared and derivatized to C-18 phase by on-column reaction with octadecyldimethyl-(N,N-diethylamino)silane. The Cls silica rods gave plate heights of 10-20 mu m for aromatic hydrocarbons in 80% methanol and 20-40 mu m for insulin in acetonitrile-water mixtures in the presence of trifluoroacetic acid, The performance of the silica rods was much better at a high flow rate than that of conventional columns packed with 5 mu m C-18 silica particles having; 12 and 30 nm pores, especially for high molecular weight species.