IMPROVED PREPARATION METHOD FOR MIXED FUNCTIONAL PHASE SILICA PACKING MATERIALS FOR LIQUID-CHROMATOGRAPHY

An improved preparation method for mixed functional phase (MFP) silica packing materials has been developed for direct injection analysis of drugs in serum. The MFP materials were synthesized from a porous silica gel having 9-nm pore-size in two steps: introduction of a phenyl phase and introduction of a glycerylpropyl (i.e. diol) phase. Bovine serum albumin was completely recovered from the MFP materials at the first injection of the protein sample. The MFP materials prepared by two steps were superior to those prepared by three or four steps [J. Chromatogr., 535, 163 (1990)] in column efficiency and in batch-to-batch reproducibility. The MFP packing materials can be used for direct injection analysis of hydrophobic and hydrophilic drugs in serum.