The use of N,N-bis(hydroxybenzyl)ethylenediamine-N,N-diacetic acid (HBED) for the determination of trivalent metal ions by capillary electrophoresis

The separation of Bi(III), Sc(III), In(III), Co(III), Ga(III), Al(III), Cr(III), Mn(III), and Fe(III) ions with HBED (Figure 1) by an ion exchange variant of electrokinetic chromatography was demonstrated. The use of high concentration of cationic polymer and a careful choice of counter ions added in carrier electrolyte allowed to stretch selectivity scale for the complete baseline resolution of all studied chelates with efficiency 40-300 thousands theoretical plates. Favorable arrangement of donor groups in HBED structure made possible the first separation of Ga(III) and In(III) chelates by CE.