Chemiluminescence detection of trace iodide with flow injection analysis of KMnO 4 ‐carbon dots system

Ultra‐weak chemiluminescence (CL) from the reaction of iodide and KMnO 4 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.