EMD Millipore 1.15389.0001 Glass Backed TLC RP-modified Silica Plate, 250µm Thick Silica Gel 60 RP-18 F254s, 20cm Width, 20cm Length (Pack of 25)

RP-modified silica layers are well suited for many separation problems that cannot be sufficiently solved by unmodified silica. In contrast to unmodified silica, RP phases do not exhibit catalytic activity and are therefore the plates of choice for unstable substances that might tend towards oxidative degradation. Furthermore, RP-modified silica plates provide ready correlation with HPLC columns and allow TLC to be used for method development and as a pilot method for HPLC. EMD Millipore RP plates RP-2, RP-8 and RP-18 are based on silica gel 60 modified with aliphatic hydro carbons of increasing hydrocarbon chain length resulting in increased hydrophobicity. The hydrocarbon chain length in combination with the degree of modification strongly affects retention: Retention of the sample and migration times increases with the higher degree of modification and with growing hydrocarbon chain in the order RP-2, RP-8, RP-18 using the same solvent composition, while RF values decrease. Additionally, with rising water content in the solvent system, retention will increase.