Separation and characterization of oxide particles by capillary electrophoresis

Abstract

Separation of oxide particles by capillary electrophoresis (CE) is a relatively unexplored area. In environmental studies the ability to separate chemically different oxides by CE would permit characterization of the composition of mixtures of such particulate species and potentially could afford concentration enhancement or isolation of particular oxides from complex particulate matrices. Knowledge of the influence of different components of particle-suspending solutions on the surface characteristics of oxides assists in optimizing separations of particulate species. The effects of phosphate, carbonate, and borate anions and the sodium ion concentration on the electrophoretic mobility of titania, hematite, and alumina are investigated. All three anion types have significant effects on the electrophoretic mobility of each of the oxides, with borate anions yielding the highest degree of selectivity between titania and alumina. An Na+ concentration of 3 mM provides the best quality oxide separations for each of the buffer systems. © 1996 John Wiley & Sons, Inc.