Application of Photogenerated Iodine for Quantitative Determination of Water-Soluble Antioxidants

A photochemical method for determination of water-soluble antioxidants was developed based on titration of the analyte by photogenerated iodine obtained by irradiating an auxiliary solution containing potassium iodide and a sensitizer at pH 5.6. Stabilization of the current in the cell indicated that the reaction went to completion because the content of titrant in the solution was monitored by voltammetry. The technique satisfied the validation criteria for linearity, precision, and accuracy. Application of the proposed method in analytical practice reduced not only the time for a single determination because solutions did not need to be standardized and routine analyses were avoided but also the cost of a single analysis because expensive equipment and reagents were not required.