C. Sarzanini et al., ION-INTERACTION CHROMATOGRAPHIC STUDIES ON METAL-IONS COMPLEXED WITH PLASMOCORINTH-B DYE, Journal of chromatography, 640(1-2), 1993, pp. 179-185
The ion-interaction chromatographic behaviour of Plasmocorinth B (a di
sulphonated azo dye) and of its complexes formed with metal ions in ox
idation states + 2 and + 3 (Cu2+, Ni2+, Al3+, Co3+, Fe3+, Ga3+) was in
vestigated. The effect of cationic ion-pairing agents (tetramethyl-, b
enzyltrimethyl- and tetrabutylammonium) was also evaluated in the pres
ence of alkali metal ions competitors (Li+ and Na+). The effects of or
ganic modifier and of pH were also considered. The remarkably differen
t behaviour of the ligand and the complexes suggests the formation of
M(II)L- and M(III)L2(2-). The stoichiometry of complexes was confirmed
by applying the electrostatic theory derived from Gouy-Chapman and a
modified Langmuir adsorption isotherm to the experimental data.