METHOD FOR THE PREPARATION OF INTERNAL-SURFACE REVERSED-PHASE PACKING MATERIALS STARTING FROM ALKYLSILYLATED SILICA-GELS

A simple method for the preparation of internal-surface reversed-phase (ISRP) packing materials was developed. Partial decomposition of alkylsilylated silica gel with an aqueous acid followed by the introduction of diol functionalities produced stationary phases possessing the properties of ISRP packing materials. The method is applicable to various types of reversed-phase packing materials irrespective of the structure of the bonded alkyl moieties. The alkyl/diol-type packing materials possess greater hydrophobic properties than other ISRP packing materials currently available for high-performance liquid chromatography. Reversed-phase separation of low-molecular-weight compounds on the alkyl/diol phase by direct injection of serum samples is demonstrated. The present packing materials prepared from relatively large particles with or without the introduction of the diol phase can also be used for open-column chromatography in the reversed-phase mode with a wide range of aqueous-organic mobile phases, as the external surfaces are wettable with water. © 1990.