RP modified plates serve two purposes: act as a pilot method for HPLC and allow to choose various solvent system for special separations. RP-modified silica layers from EMD Millipore are well suited for many separation challenges that unmodified silica cannot overcome. These layers use aqueous solvent systems to separate extremely non-polar substances and analyze particular polar substances that can adapt to ion-pair chromatography. What’s more, RP-modified silica layers are less dependent on atmospheric humidity. Unlike unmodified silica, RP-phases do not exhibit catalytic activity. This makes them the plates of choice for unstable substance that tend to experience oxidative degradation.