Anodic voltammetric behavior of iodide at a chitosan-modified glassy carbon electrode

A novel anodic stripping voltammetry for the determination of iodide with a chitosan-modified glassy carbon electrode (CMGCE) has been described. The CMGCEs were able tot preconcentrate: iodine due to the oxidation of iodide at + 0.7 V (vs. SCE) in pH = 3.80 sulfuric acid, after equilibration at + 0 .1 V for 25 s, an anodic scan was performed from + 0.1 to + 1.2 V at 100 mV /s, and a well-defined peak could be obtained at about + 0.85 V. The peak c urrent also varied linearly with the concentration of iodide over the range 0.1 similar to 0.75 mug/mL, and the detection limit was 0.05 mug/mL. The c onditions for determining iodide and the possible electrode reaction proces ses were discussed. The method has been applied to the detection of iodide in cydiodine tablets with satisfactory results.