Chemiluminescence detection of trace iodide with flow injection analysis of KMnO4 -carbon dots system.

Ultra-weak chemiluminescence (CL) from the reaction of iodide and KMnO4 was strongly enhanced by carbon nanodots (CNDs) in an acidic medium. The CL intensity was directly proportional to the concentration of iodide in the solution. Therefore, a flow-injection CL system with high sensitivity, selectivity and reproducibility is proposed for the determination of iodide. The proposed method exhibited advantages over a linear range of 3.0 × 10-6 -1.0 × 10-4  mol/L and had a detection limit of 3.5 × 10-7  mol/L. The method was successfully applied to the evaluation of iodide in food samples with recoveries of between 96 and 103%. The relative standard deviations were 2.1 and 4.1% for intra- and inter-assay precision, respectively.