Determination of Toxic Trace Metals Pb, Cd, Ni, and Zn in Soil by Polarographic Method

The concentrations of toxic trace metals in the soil sample collected from Jaipur, India, have been determined using Direct current Polarography (DCPolarography). Using DC polarograms of dry digested Soil sample in acetate buffer (pH=4.7) and HCl (pH=2.5), quantities of Pb, Cd, Ni and Zn were determined. Half wave potentials were -1.00 V, -0.61 V, -0.41 V and -0.91 V for zinc, cadmium, lead and nickel, respectively. The heavy elements quantities in digested soil samples were as follows: Pb about 7.70 ppm, Cd 7.35 ppm, Ni 2.41 ppm and Zn 2.68 ppm.