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

This paper covers the preparation of a sol-gel-derived macrocyclic dioxopol yamine (1, 4, 7,10-tetraazaclotridecane-11,13-dione) stationary phase for o pen-tubular capillary electrochromatography (OTCEC). The sol-gel-derived ma crocyclic dioxopolyamine capillary columns have shown improved separations of neurotransmitters, isomeric nitrophenols, isomeric dihydroxybenzenes, is omeric aminophenols, isomeric diaminobenzenes and three ortho-halogen anili nes, in comparison with those of untreated capillaries. The characteristics of the sol-gel;derived macrocyclic dioxopolyamine capillary columns are co mpared with the capillary column modified with the macrocyclic dioxopolyami ne by chemically bonded method after etching. The sol-gel method provided a porous silica material with stationary phase in place within the same expe rimental procedure. This provided speedy fabrications of high-efficiency co lumns with high surface area and improved phase ratio. We achieved high eff iciencies of 60 000-340 000 plates/m for the various isomeric compounds. Th e reproducibility migration time and the plate number were pretty good.