Silica Monolith Particles of Improved Separation Efficiency and Their Modification with Polystyrene by RAFT Polymerization

초록

Silica monolith particles of ca 2μm size having proper particle size distribution were prepared and modified to give polystyrene attached silica monolith particles as a new chromatographic stationary phase of high separation efficiency. Attachment of 4-chloromethylphenylisocynate to silica particles was catalyzed by dibutyltindichloride and the ligand was reacted with diethyldithiocarbamate to yield initiator attached silica particles. Reversible addition-fragmentation chain transfer (RAFT) polymerization was used to attach polystyrene layers to initiator attached silica monolith particles. This new stationary phase was packed in a microcolumn of 0.5 mm ID and its separation performance was examined. The optimum flow rate was found 7 uL /min in 60/40 (v/v) acetonitrile /water (0.1 % TFA). The numbers of theoretical plates of the column (0.5 300 mm) were over 30,000.