Energy-efficient and environment-friendly method to prepare monodispersed silica stationary phases for simultaneous separation of compound drugs.

An energy-efficient and environment-friendly approach to prepare porous monodispersed micro-sized silica particles with methyltrimethoxysilane (MTMS) as the precursor is described. The particles were synthesized by a two-step hydrolysis/condensation procedure, with post-synthetic aging and calcination for methyl group removal. They show uniform spherical morphology, narrow particle size distribution (D/, 1.2-1.6), tailored particle size (3, 5, 7 μm) and mesopore structure (10, 13 nm), which can be directly used as packing materials for HPLC without size classification. C, sulfonate, and C/sulfonate mixed-mode stationary phases were produced by a green vapor deposition method based on the synthesized silica particles. The newly synthesized C phase exhibits mechanical stability, kinetic behavior and separation performance expected from the commercial C column. The C/sulfonate phase exhibits prominent mixed-mode retention behavior which can be applied to the simultaneous separation of multiple substances in the compound drugs.