Determination of Lead(II) by Constant Current Stripping Chronopotentiometry Using Bismuth Film Electrode after Extraction of the Bromide Complex into Propylene Carbonate

A selective and simple method is presented for the determination of Pb(II) by constant current stripping chronopotentiometric analysis (CCSCP) using bismuth film electrode. This method is based on the extraction of the bromide complex into propylene carbonate, followed by CCSCP measurements in the organic phase. CCSCP studies revealed that Pb(II) gave a characteristic response at about −0.52 V vs. Ag/AgCl on the stripping chronopotentiogram (dt/dE curve) after recording a potential vs. time curve at 3.0 μA. The peak height of Pb(II) response was directly proportional to the initial metal concentration of the aqueous phase in the ranges of 1.0–22.0 μg dm−3 (correlation coefficient 0.997) when the optimized parameters were used. A detection limit (S/N=3) of 0.0880 μg dm−3 Pb(II) was obtained at 180 s deposition time. The relative standard deviation was 3.2% on replicate runs (n=12) for the determination of 10.0 μg dm−3 Pb(II). Analysis of certified reference materials has confirmed the applicability of the proposed method for determination of Pb(II) in soil and water samples.