| The research on the preparation of the traditional chromatography packing is more mature.The balance time of the column is long.The column efficiency,column pressure and the speed of analysis are mutually restricted,which can not meet the requirements of modern separation and analysis.The new high purity silica packing has the characteristics of high column efficiency,low column pressure and fast separation speed.That's wide application prospect.In this paper,the preparation process and influence factors of the key material which is silica sol and silica gel about core shell silica packing were investigated.The separated ability of the packing material was evaluated,and the following results were obtained:?1?The silica sol was product with sol-gel method,silica partical size,viscosity,silica solid content and gel time were determined.The best product conditions of silica sol is ammonia 15 ml,temperature 10 ?,water 120 ml,TEOS 208 g.?2?In preparation of silica sol as raw material,the high pure silica was product with polymerization induced colloid aggregation method?PICA?,the silica particle size,specific surface area and pore size were characterized to determine the best of silica product conditions is 15 nm silica sol,2 molar ratio of formaldehyde to urea,pH 0.4 and reaction time of 10 minutes.?3?The core-shell SiO2/SiO2 silica microsphere was product with layer-by-layer method.The C18 fixed phase was obtained by bonding the C18 functional group,and the performance was compared with traditional C18 column.The results showed that core-shell equivalent column efficiency is two times better than 3 ?m that a conventional column;three times better than 5 ?m one.The core-shell column pressure is three fifths of the 2 ? m conventional chromatographic column,between core-shell and 3 ?m one column pressure is equal.In the same efficiency and degree of separation case,core-shell chromatography analysis speed is two times faster than 3 ? m one,and three times faster than 5 ? m column. |
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