CALCON ADSORPTION AND ITS USE IN THE POLAROGRAPHIC-DETERMINATION OF IRON(III)

Calcon exhibits polarographic activity and gives two waves, one of whi ch is much higher than the other. The irreversible reduction of Calcon is due to its adsorption on a dropping mercury electrode. The paramet ers of adsorption were calculated. Studying the effects of the medium pH, the composition of the supporting electrolyte, and some metal ions suggested that the tautomeric equilibrium of Calcon shifts in the pre sence of iron(III). A procedure for the polarographic determination of iron based on this effect was proposed, The calibration graph was lin ear over the range 4 x 10(-7) to 4 x 10(-6) M iron(III) under the cond itions of alternating-current polarography with 4 x 10(-5) M Calcon pr esent.