Micellar electrokinetic chromatographic separation of Fe(II)/Fe(III) and Cu(I)/Cu(II) as 2-pyridylazo chelates

Fe(II)/Fe(III) and Cu(I)/Cu(II) are electrophoretically separated as chelat es of 4-(2-pyridylazo)resorcinol (PAR), 2-(5-bromo-2-pyridylazo)-5-diethyla minophenol (5-Br-PADAP), and 4-(3,5-di-bromo-2-pyridylazo)-N-ethyl-N-(3-sul fopropyl)aniline (3,5-diBr-PAESA). Micellar media are suitable for the pres ervation of the original oxidation states of metal ions during the separati ons. Some essential aspects of these chelates, which are not clearly shown by spectrophotometric studies, are elucidated by the present separations, ( C) 1999 Academic Press.