Embedded with a Polar Functional Group. Shim-pack GIS RP-Shield contains a polar functional group embedded between silica surface and an octadecyl group, making it stable in 100% aqueous mobile phases without phase collapse. The embedded polar functional group is also extremely base deactivated, which enables the column to provide superior peak shape for acids. Shim-pack GIS RP-Shield provides unique selectivity as hydrogen bonding interactions, making it suitable for separations that cannot be achieved by other modes, such as hydrophobic interactions or pi-pi interactions. Bonded Phase Octadecyl Groups, Particle Size 5 ?m, Pore Size 10 nm, Surface Area 450 m2/g, Carbon Loading 9 %, End-capping No, pH Range 2 - 7.5, USP Code L1.