Core-shell particles consist of a nonporous core inside a porous shell. By using these core-shell particles, one can achieve sharper peaks compared to fully porous silica gel particles of the same diameter. Compared to fully porous particles, core-shell particles have a more uniform particle diameter therefore, core-shell particles can be packed in the column more uniformly to minimize sample diffusion.
COSMOSIL PBr column is packed with pentabromobenzyl-bonded silica that enables separation by dispersion force interaction. COSMOSIL PBr retains hydrophilic compounds stronger than C18 columns under the same reversed-phase conditions. COSMOCORE 2.6PBr can separate compounds with similar hydrophobicity, utilizing several kinds of molecular interactions, including dispersion force generated by the bromine atoms.