N. Guan et al., Open tubular capillary electrochromatography in fused-silica capillaries chemically bonded with macrocyclic dioxopolyamine, ANALYT CHIM, 418(2), 2000, pp. 145-151
In this paper, the macrocyclic dioxopolyamine compound: 1,4,7,10-tetraazacy
clotridecane-11,13-dione was used as stationary phases with the aid of 3-(2
-cyclooxypropoxyl)propyl-trimethoxy silane as bridge in open-tubular capill
ary electrochromatography (OTCEC). To increase the surface area and produce
radial extensions from the surface, the capillaries were etched by aqueous
sodium hydroxide before being coated. A comparison was made of the propert
ies of capillary modified with the macrocyclic dioxopolyamine with those of
the bare capillary by electroosmotic flow measurements and its dependence
on pH. The direction of EOF on the capillaries modified with dioxo[13]aneN(
4) is reversed at somewhat lower pH (pH<5.23). These modified capillaries h
ad shown improved separations of neurotransmitters, isomeric nitrophenols,
isomeric dihydroxybenzenes and isomeric aminophenols, in comparison with un
treated capillaries. The plate numbers of the isomeric nitrophenols and dih
ydroxybenzenes were greater than 20,000/m and the reproducibility of migrat
ion time and the plate number was pretty good (R.S.D.<2.5%). (C) 2000 Elsev
ier Science B.V. All rights reserved.