| Summary: | <p class="orbitalabstract">In this work, bismuth films were electrodeposited in situ onto carbon paste electrodes (CPEs) and they were used for lead determination in tap water samples by anodic stripping square wave voltammetry. The analytical performance of CPEs prepared with different binder agents was compared. It was observed that CPEs prepared with solid paraffin as binder agent provided the best results. All parameters of the analytical method were optimized and the best conditions obtained were: acetate buffer 0.1 mol L<sup>-1</sup> (pH=4.75) as supporting electrolyte; pre-concentration time of 240 s and electrodepositing potential of -1.2 V vs. Ag/AgCl/KCl<sub>sat</sub>. The best Bi<sup>3+</sup> concentration was 2.0 μmol L<sup>-1</sup>. At these optimized conditions, analytical curves were constructed and two linear regions were obtained: 25 to 100 nmol L<sup>-1</sup> and 250 to 1000 nmol L<sup>-1</sup>. Detection limits (LD) corresponding to these linear ranges were, respectively, 5.77 and 52.3 nmol L<sup>-1</sup>. Recovery experiments were performed in tap water samples and recovery percentages close to 100 % were always obtained although the best results were obtained for samples spiked with 250 nmol L<sup>-1</sup> of Pb<sup>2+</sup>.</p> <p class="orbitalabstract"><strong> </strong></p>
|
|---|
