Ultra-trace levels voltammetric determination of Pb in the presence of Bi at food samples by a FeO@Schiff base Network modified glassy carbon electrode.

In this research, a highly sensitive electrochemical sensor was developed for the square wave anodic stripping voltammetric determination of Pb at ultra-trace levels. A Glassy carbon electrode was modified with an in-situ electroplated bismuth film and the nanocomposite of a recently synthesized melamine based covalent organic framework (schiff base network (SNW)) and FeO nanoparticles (FeO@SNW). The obtained results exhibit clearly that combination of FeO@SNW and in-situ electroplated bismuth film enhances the sensitivity of the modified electrode towards Pb remarkably. A Plackett-Burman design was implemented for screening experimental factors to specify the significant variables influencing the sensitivity of the electroanalytical method. Afterward, the effective factors were optimized using Box-Behnken design (BBD). Under optimized conditions, the proposed electrode showed a linear response towards Pb in the concentration range of 0.003-0.3 μmol L with the detection limit of 0.95 nmol L. The selectivity of the fabricated electrode towards different ionic species were checked out and no serious interference was observed. At the end, the application of the designed sensor in the determination of Pb at 10 different edible specimens were investigated and the obtained recovery values were in the range of (95.56-106.64%) indicating the successful performance of the designed sensor.