The GIS C18 column has a high surface area for strong hydrophobic interaction, increased retention, and low adsorption of ionic compounds. Highly uniform particles ensure stable mobile phase delivery and symmetrical peak shapes. USP L1, pore size: 100A, surface area: 450 m2/g, 15% carbon load, pH range: 2 to 7.5, fully endcapped. Method development on an analytical GIS C18 column is highly recommended before purchasing a prep column. Prep columns cannot be returned or exchanged once used. A guard column is recommended to prolong the life of the prep column. Replacement for Premier C19 220-91199-14.