Separation materials for thin layer chromatography

Claim 1

A process for controlling water wettability from easily wettable to just wettable of a separation material sized and dimensioned for thin layer chromatography and comprising a carrier material coated with an absorbent silica gel layer whose surface has been modified by reaction with a silanizing agent, comprising, prior to the silanization step, homogeneously doping the silica gel surface by completely impregnating it with a solvent solution of a catalyst effective for catalyzing the silanization reaction of the silica gel surface with the silianization agent, said silica gel surface being doped to a preselected extent, solvent washing the resultant doped silica gel layer of excess catalyst prior to the silanization reaction, and adjusting the water wettability of the separation material by adjusting said impregnation step to achieve a degree of covering of the silica gel surface with an amount of catalyst effective to produce a degree of silanization of 0.15-0.8 μmol/m 2 for reversed phase materials or 1.2-2.5 μmol/m 2 for hydrophilic materials, the less the extent of covering the higher the degree of water wettability.