Preparation and Characterization of SiO2/SiO2 Core–Shell Microspheres as RP-HPLC Stationary Phase

Abstract

Novel SiO2/SiO2 core–shell monodisperse silica spheres for high-performance liquid chromatography packing materials are prepared by the layer-by-layer self-assembly technique. The core–shell silica spheres consist of micrometer-sized porous silica spheres as the core and a thin mesoporous silica shell formed from multilayer nanometer-sized silica particles. In addition, a reversed-phase packing by bonding octadecyltrichlorosilane on SiO2/SiO2 particles through alkyl-modified method is prepared and characterized. The results show that the carbon content of the new reversed-phase stationary phase increases by approximately 45% compared with the uncoated octadecyl-bonded SiO2 stationary phase. Eight kinds of tested aromatic compounds are well-separated on the packing and the peaks are symmetrical, which demonstrates that the packing acts as an excellent reversed-phase chromatographic stationary phase.