Mj. Thornton et Js. Fritz, SEPARATION OF INORGANIC ANIONS IN ACIDIC SOLUTION BY CAPILLARY ELECTROPHORESIS, Journal of chromatography, 770(1-2), 1997, pp. 301-310
Citations number
11
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Inorganic anions are almost always determined by capillary electrophor
esis (CE) at an alkaline pH, so the analytes will be fully ionized. Ho
wever, a long-chain quaternary ammonium salt usually must be added as
a flow modifier to the carrier electrolyte to reverse the direction of
the electroosmotic flow. By working at a sufficiently acidic pH, the
electroosmotic flow in fused-silica capillaries is virtually eliminate
d, and anions can be separated simply by differences in their electrop
horetic mobilities. Excellent separations were obtained for AuCl4- and
the chloro complexes of platinum group elements in HCl solution at pH
2.0 to 2.4. No additional buffer or flow modifier was needed. This CE
technique is an excellent way to follow slow hydrolytic reactions in
which one or more of the chloride ligands is replaced by water. Sharp
peaks and good separations were also obtained for MnO4-, VO3-, chromat
e, molybdate, ferrocyanide, ferricyanide and stable complex ions such
as chromium oxalate (CrOx(3)(3-)).