Preparation and Characterization of Biphenylene Bridged Hybrid Monolithic Column for Capillary Electrochromatography
Biphenylene-Bridged Hybrid monolithic column was synthesized for the capillary electrochromatography by a two-step acid/base-catalyzed hydrolysis/co-condensation of phenyltriethoxysilane(PTES) and 1,4-bis(triethoxysilyl)benzene(BTEB) using hydrochloric acid and dodecylamine as catalysts,respectively.The influences of determining factors in the sol-gel process such as the monomer ratio,pH and the water content on the monolith formation were systematically investigated.The structure and pore size distribution of the monolithic column were characterized by scanning electron microscopy, IR spectroscopy and mercury porosimetry,respectively.The median pore diameter of the monolith was around 3.4 m with pore volume of 3.5 cm3/g.Chromatographic characteristics of the monolithic column prepared with the optimized fabrication condition were studied.Alkylbenzenes,polycyclic aromatic hydrocarbons(PAHs),anilines and positional isomers of phenols were successfully separated on the functionalized silica monolithic column.Run-to-run,and column-to-column reproducibilities of the monolithic columns were investigated in terms of t0 and the retention time and capacity factor of six alkylbenzenes.It was observed that the RSDs were less than 0.6% and 0.3%(n=8)for run-to-run,and the RSDs were less than 7.2% and 5.6%(n=3)for column-to-column,respectively.These results indicated that the reproducibility of the monolithic columns was quite satisfactory.