HxSil C18 Analytical Guard Column Starter Kit (1 holder, 2 cartridges), Stainless SteelSilica packing material for a variety of reversed phase separations Hamilton HxSil C18 columns are well end capped for retention time reproducibility and durability. HxSil C18 columns exhibit greater retention than most columns and enhances the separation of compounds that are not sufficiently retained on other C18 columns. Application Examples: Polycyclic aromatic hydrocarbons, small organic molecules. HxSil C18 Overview Alkylated silica is used for