Preparation and evaluation of octadecyl-treated porous glasses : Application to the determination of methotrexate in serum

Abstract The retention and selectivity of methotrexate (MTX) in serum were studied by high-performance liquid chromatography on octadecyl-treated porous glasses and silicas. From elemental analysis data for carbon, the maximum number of bonded octadecyl surface groups per gram (mean pore diameter 153 A, specific surface area 193 m 2 /g, pore volume 0.83 ml/g) in octadecyl-treated glass was calculated to be 0.131 × 10 21 . MTX in human serum could be separated on both glasses and silicas with methanol-acetate buffer mixtures as eluents.