Analysis of metal complexes by capillary electrophoresis Effect of organic additives on separation of highly hydrophobic complexes

In this paper it was demonstrated that Ru(III), Rh(III) Os(IV) and Co(II) were separated as their 4-(2-thiazolyazo)resorcinol (TAR) complexes by capillary electrophoresis coupled with pre-column derivatization scheme. Some separation parameters such as buffer acidity, buffer concentration, injection time and applied voltage were investigated and optimized. Emphasis was placed on the effect of organic additives introduced into running buffer on the electrophoretic separation. Under the chosen separation conditions, a separation of the four metal complexes was accomplished in 20min together with the ligand TAR. The detection limits (S/N=2) of Co(II), Ru(III), Rh(III) and Os(IV) were 92, 294, 843 and 510ng/ml, respectively.