EFFECT OF ETHYLENEDIAMINE ON THE ANODIC-STRIPPING VOLTAMMETRIC DETERMINATION OF HEAVY-METALS IN THE PRESENCE OF HUMIC-ACID

Ligand competition coupled with differential pulse anodic stripping vo ltammetry has been investigated for the determination of copper, lead and cadmium. Ethylenediamine displaces humic acid in its metal complex es forming kinetically labile compounds. It also eliminates interferen ces associated with the oxidation of copper. This enhances the sensiti vity of the determination of the metals over a wide range of humic aci d concentration (up to 30 mg/l). The procedure has been applied to the determination of heavy metals in a real water sample.