COMPLEXATION OF LEAD WITH HUMIC MATTER BY STRIPPING VOLTAMMETRY - PREVENTION OF ADSORPTION ON NAFION-COATED MERCURY FILM ELECTRODE

The complexation of humic matter with lead in natural water conditions was studied by differential pulse anodic stripping voltammetry (DPASV ) using a mercury film of a Nafion-coated mercury film as the working electrode. The results clearly show that the Nafion film greatly minim izes the adsorption of humics on the electrode. Besides adsorption, ot her effects on the voltammetic signal are discussed, such as the degre e of lability, ligand heterogeneity, and the metal-to-ligand concentra tion ratio at the electrode surface.