Silica based material

Stationary phase separation material comprising an organo-modified silica based material comprising an inner part which is unmodified silica, and a part which is silica comprising organic groups bonded to the silica, wherein said organic groups are distributed from the surface of the silica based material, including pore surfaces, into the silica based material in a gradually decreasing concentration, which further comprises a surface-functionalisation of the organo-modified silica based material in the form of one or more functional groups, and wherein the stationary phase separation material has an alkaline stability, determined as ppm silicon per specific surface area (BET method) [ppm Si/m2/g] in the eluate from the procedure of pumping 41.5 mL of 100 mM NaOH mixed with ethanol in a 1:1 volume relation, at 1 mL/min, at a temperature of 25° C., through a column of 215 mm length and 4.6 mm inner diameter packed with about 2.5 g of the organo-modified silica based material, of less than about 0.2 [ppm Si/m2/g] wherein the ratio of the amount of silicon atoms having a T2 structure to the amount of silicon atoms having a T3 structure is less than about 1, as determined by solid state NMR spectroscopy.

Stationary phase separation material comprising an organo-modified silica based material comprising an inner part which is unmodified silica, and a part which is silica comprising organic groups bonded to the silica, wherein said organic groups are distributed from the surface of the silica based material, including pore surfaces, into the silica based material in a gradually decreasing concentration, which further comprises that the organo-modified silica based material has been subjected to (i) surface-functionalisation and (ii) end-capping wherein the ratio of the amount of silicon atoms having a T2 structure to the amount of silicon atoms having a T3 structure is less than about 1, as determined by solid state NMR spectroscopy.