Sol-gel-derived macrocyclic dioxopolyamine stationary phase for open-tubular electrochromatography

This paper covers the preparation of a sol-gel-derived macrocyclic dioxopolyamine(1,4,7,10-tetraazaclotridecane-11,13-dione) stationary phase for open-tubular capillary electrochromatography (OTCEC). The sol-gel-derived macrocyclic dioxopolyamine capillary columns have shown improved separations of neurotransmitters, isomeric nitrophenols, isomeric dihydroxybenzenes, isomeric aminophenols, isomeric diaminobenzenes and three ortho-halogen anilines, in comparison with those of untreated capillaries. The characteristics of the sol-gel-derived macrocyclic dioxopolyamine capillary columns are compared with the capillary column modified with the macrocyclic dioxopolyamine by chemically bonded method after etching. The sol-gel method provided a porous silica material with stationary phase in place within the same experimental procedure. This provided speedy fabrications of high-efficiency columns with high surface area and improved phase ratio. We achieved high efficiencies of 60 000-340 000 plates/m for the va rious isomeric compounds. The reproducibility migration time and the plate number were pretty good.