The invention discloses a radial mesoporous core-shell
silica microsphere modified C18 chromatographic filler with adjustable shell thickness as well as a preparation method and application thereof, and belongs to the technical field of
chromatographic separation materials. The method comprises the following steps: dispersing monodisperse non-
porous silicon dioxide microspheres, a template agent and an
electrolyte in a water phase, and adding a basic catalyst to form a
uniform system; then adding an
oil phase, a pore-enlarging agent and a
silicon source, carrying out a reaction on an oil-water two-phase interface, and carrying out in-situ growth on the surface of the
microsphere to form a
silicon dioxide shell layer with a radial mesoporous structure by adjusting at least one parameter of the addition amount of the
silicon source, the addition amount of the
electrolyte and the volume ratio of water to oil so as to realize regulation and control of the thickness of the shell layer; and carrying out post-treatment to remove the template agent, carrying out acidification activation, and carrying out a reaction with octadecyl
trichlorosilane to carry out C18 bonding so as to obtain the target chromatographic filler. The filler has a monodisperse core-shell structure, and the thickness of a shell layer can be accurately regulated and controlled in a range of 90.78 nm to 251.93 nm. The filler disclosed by the invention shows high column efficiency, rapid separation and good stability on alkylbenzene,
polycyclic aromatic hydrocarbon and
phthalate compounds in a reversed-phase
chromatography mode.