Effect of micelles on the chemical speciation of binary complexes of Co(II), Nii(II), Cu(II) and Zn(II) with succinic acid

Abstract

Speciation of Co(II), Ni(II), Cu(II) and Zn(II) complexes with succinic acid in the presence of anionic, cationic and non-ionic surfactants at an ionic strength of 0.16 mol dm-3 and temperature 303 K were investigated pH metrically. The existence of different binary complex species was established from modelling studies using the computer program MINIQUAD75. The decreased stability of the complexes with increasing micellar content was explained by electrostatic forces. The influence of the micelles on the chemical speciation is discussed based on the mole fraction of the medium. Distribution diagrams of various species of the complexes in relation to pH are presented.

Keywords

• succinic acid
• speciation
• essential metals
• binary complexes
• micelles