Synthesis of a mixed-functional silica support for direct injection analysis of drugs in serum by liquid chromatography

Summary A new mixed-functional silica material has been developed for direct injection analysis of drugs in serum. The mixed-functional material is synthesized from porous silica by three steps; introduction of 3-glycidoxypropyl groups, introduction of phenyl groups, and hydrolysis of the oxirane ring to diol groups. The prepared column packing can be used for direct injection analysis of hydrophobic and hydrophilic drugs in serum over the eluent pH range employed for ordinary siloxane-bonded silica. The recovery of drugs from serum was almost 100%, regardless of the difference in their protein bindings.