Analytical Sciences

Sensitive Flow-Injection Amperometric Detection of Iodide Using Mn³⁺ and As³⁺

Snezana D. NIKOLIC, Jelena J. MUTIC, Aleksandar D. LOLIC, and Dragan D. MANOJLOVIC

Department of Analytical Chemistry, Faculty of Chemistry, P. O. Box 550, 11001 Belgrade, Serbia and Montenegro

A rapid, selective, and sensitive kinetic flow-injection method for iodide content determination with amperometric detection on a platinum electrode was developed. The method is based on the catalytic effect of iodide on the Mn³⁺ reaction with As³⁺ in the presence of sulfuric acid. The calibration curve was linear in the concentration range from 5.0 × 10^-7 to 1.0 × 10^-4 mol/L iodide. The limit of detection (LOD) was found to be 5.0 × 10^-9 mol/L iodide. The relative standard deviations (RSD) were 1.68% and 3.03% for 1.0 × 10^-3 mol/L standard and 1.0 × 10^-6 mol/L iodide solution (n = 6), respectively. The method has been successfully applied for determination of iodide in waters, table salts, fodder, organic substances and human blood sera. The results were compared with those obtained by a standard AOAC (Association of Official Analytical Chemists) method, as well as with those obtained by a kinetic spectrophotometric procedure for determination of iodide.

J-STAGE: View this article in J-STAGE