Open Tubular Monolith Formation and C18 Ligand Immobilization in Silica Capillary by Microwave Heating for Capillary Electrochromatography

摘要: The methods of C18 modification to silica gel are well described in the literature. Three known by which three different types stationary phases obtained, respectively-a brush form, an oligomeric and a bulk form. form is composed separate monomeric ligands chemically attached surface, obtained reaction with monochlorodimethyloctadecylsilane. where oligomer bonded each silanol site dichloromethyloctadecylsilane. 3 dimensional polymer-like network, trichlorooctadecylsilane. In all cases, endcapping generally required after prevent tailing phenomenon chromatographic separation. forms not widely used commercial products because preparation such demands drastic time-consuming reactions at high temperatures. On other hand, easy make under mild conditions, used. Spherical porous most common material for support that gives separation efficiencies. Microwave techniques have been chemical synthesis derivatization, nano materials, extraction, sample treatment dissolution, etc. application has expanded even polymerization immobilization polymer coating on phases. heating often cause fast good results owing rapid uniform heating. However, microwave monoliths or ligand reported so far. Recently, monolithic column raised lot interest liquid chromatography. one-body solid structure nanometer-sized inner pores micrometer-sized through channels. Particularly, monolith carried out capillary it electrochromatography (CEC). Open-tubular columns significant advantages over their packed counterparts simplicity hasslefree fritless operation. Column efficiencies 100 000 theoretical plates per meter open tubular CEC 50 μ ID, up half million sol-gel open-tubular 10-13 ID. this study, effects studied comparison thermal prepared processes-1) formation immobilization; 2) 3) immobilization. Their performances comparatively studied. method OT (open tubular) was much faster than heating, thickness layer thinner