Voltammetric Detection of Lead Using Chitosan-tripolyphosphate Crosslinked Electrode

Voltammetric Determination of Lead and Copper in Wine by Modified Glassy Carbon Electrode

This paper describes the determination of Pb and Cu with a Nafion-modified glassy carbon electrode and MnCo₂O₄ nanoparticles as working electrode for anodic stripping voltammetry. Pb and Cu were accumulated in HCl/KCl (0.1 mol dm^-3) at a potential of -1.4 V (vs. Ag/AgCl electrode) for 480 s, followed by a linear sweep anodic stripping voltammetry (ASV) scan from -1.0 to +0.5 V. Under optimum conditions, the calibration curves were linear in the range of 0.01 - 8 and 0.01 - 5 mg dm^-3 for Pb and Cu, respectively. Effect of sample dilution, accumulation time and potential were optimized. A study of interfering substances was performed. A significant increase in current was obtained at the modified electrode in comparison with the bare glassy carbon electrode. The modified electrode was successfully applied for determination of Pb and Cu in wine samples after a simple preparation procedure. Pb and Cu content in wine was used for estimation of the target hazard quotient (THQ) values for minimal and maximal levels of the metals.

Amperometric Sulfite Sensor Using Electrodecorated Pt Particles onto an Aminated Glassy Carbon Electrode Prepared by Stepwise Electrolysis

A novel modified glassy carbon electrode with platinum (Pt)-electrodecorated and nitrogen-containing functional groups was prepared by stepwise electrolysis. The prepared electrode exhibited electrocatalytic activity towards sulfite oxidation that was better than that of a bare glassy carbon electrode. The electrocatalytic activity of sulfite oxidation has been applied to an amperometric sulfite sensor. A favorable linear relationship between the current response (ΔI) and the sulfite concentration up to 500 μM was exhibited. The detection limit was estimated to be 3 μM based on the criterion of a signal-to-noise (S/N) ratio of 3 under optimized conditions. In regards to the reproducibility, the RSD (n = 10) was 8.9% for 80 μM sulfite.