SUBSTITUTED CATECHOLS AS COMPLEXING AGENTS FOR THE DETERMINATION OF BISMUTH, LEAD, COPPER AND CADMIUM BY ADSORPTIVE STRIPPING VOLTAMMETRY

Copper, cadmium, lead and bismuth (>5 mu g ml(-1)) are determined by a dsorptive cathodic stripping voltammetry (AdCSV) on a mercury film gla ssy carbon electrode, using catechol, 4-methylcatechol, 4-t-butylcatec hol and resorcinol as complexing Ligands. Complexes of lead, copper an d bismuth with resorcinol showed the largest increase in current with increase in metal concentration, whereas complexes of these metals wit h 4-t-butylcatechol showed the lowest current response. Cadmium showed a different behaviour from the other three metals in that the highest current response was observed with 4-methylcatechol. The four metals could be determined simultaneously in the presence of resorcinol, alth ough considerable interference was observed between bismuth and copper .