High quality separations of three-component mixtures of suspended micromete
r-size metal oxide particles have been achieved by capillary zone electroph
oresis in two different high-pH aqueous buffer systems. Mixtures of Al2O3,
Fe3O4 and TiO2 and of Al2O3, Fe3O4 and Fe2O3 were separated in 5-10 min in
either carbonate buffer, pH 10.6 or pyrophosphate buffer, pH 10.2. The effe
cts of electric held strength, buffer concentration and buffer type on sepa
ration quality were determined. Under optimized conditions, the separations
were nearly baseline resolved. Complete separation of a mixture of Al2O3 a
nd UO2 particles was also accomplished. Different sized particles/aggregate
s of a given oxide were found to co-migrate so that, for the systems studie
d, particle size effects were negligible and the separations were electroph
oretic in nature. Reproducibilities of migration times and peak widths, hei
ghts and shapes were found to be excellent, with relative standard deviatio
ns of migration times consistently being <1%. Published by Elsevier Science
B.V.