Abstract: A new convenient synthetic method was developed for the preparation of restricted-access material belonging to the group of the internal surface reversed-phase supports, which can be used for the direct injection and analysis of complex biological samples such as plasma samples. The supports, owning the function of reversed-phase chromatography, have an alkyl-chain only to the internal surfaces of the porous silica. Polyvinyl alcoholic groups chemically bound to the external surfaces of the porous silica that has the ability of hydrophilicity. Its structure was characterized by elemental analysis and electron microscope observation. The reversed-phase chromatographic performance was evaluated by using different solute probes, including propranolol, atenolol, phenobarbital and carbamazepine. Meanwhile, the comparative study with Merck Company’s ADS columns was carried out to prove capability of removing protein. At the same time, the plasma sample of propranolol was applied for the determination by direct injections. The results showed that the new internal surface reversed-phase restricted-access material owned the capabilities of protein exclusion and reversed-phase stationary, which could come true the double functions of excluding biomacromolecules and enriching micromolecule analysis. It can be used as a pretreatment column, which has the ability of on-line and fast analyzing biological specimen by direct probe inlet.

Key words: evaluation, high performance liquid chromatography (HPLC), plasma samples, preparation, propranolol, internal surface reversed-phase restricted-access material