Electrochemical Studies on Complexation and Speciation of Copper(II) in ppb Level with 1,10-Phenanthroline in Aqueous Media (original) (raw)

Complexation and speciation of copper (II) in ppb level with 1,10-phenanthroline (L) in aqueous media have been investigated by differential pulse anodic stripping voltammetry using thin mercury film glassy carbon electrode (TMFGCE). The work was carried out at constant ionic strength of 0.01 mol dm-3 using NaNO3 at ambient temperature. The pH was kept constant at 9.12 ± 0.10 by the addition of borate buffer. Applying the concept of DeFord and Hume, the stability constants of different species of copper with 1,10-phenanthroline were calculated from the variation of peak potential and diffusion current of simple and complexed metal ions under the present experimental conditions. It was found that copper(II) form three complexes (1:1, 1:2 and 1: 3; metal : ligand) with 1,10-phenanthroline. The overall stability constant of copper complexes, MLn can be defined as βMLn= [MLn ]/[M2+][L]n in which M2+ = Cu2+ and L = 1,10-phenanthroline; n is an integer. The values of the stability constan...