Submicron sized organo-silica spheres for capillary electrochromatography

Spherical, non-porous organo-silica materials in the submicron size range w ere synthesized by sol-gel processing and tested for capillary electrochrom atography (CEC). The organo-silica spheres were prepared by copolymerizatio n of alkyltriethoxy-silanes and tetraethoxysilane under ambient conditions. The synthetic approach provides silica spheres that are uniform in size (< 10% R.S.D.) and contain organic moieties (e.g., C-8) ready to be used as s tationary phase for CEC, eliminating the step of stationary phase attachmen t after particle fabrication. The final particle size is controlled by the water concentration in the initial reaction mixture. The particles were cha racterized using transmission electron microscopy, gas adsorption, and FT-I R. Fast CEC separations with high efficiency can be achieved using the fabr icated submicron particles.