Flow injection amperometry for the determination of iodate in iodized table salt

A very simple flow injection amperometric system for determination of iodate has been developed. Cyclic voltammetry was used to study reactions of iodate, iodide and iodine on a glassy carbon electrode. A single line manifold of the flow system consists of a pulse-free reagent propulsion using a simple Mariotte bottle, a home-made injection valve, and a cross flow electrochemical cell with a potentiostat for control a potential of glassy carbon working electrode at +200mV versus Ag/AgCl electrode. Using a solution of 1.0% w/v NaCl, 0.02% w/v KI and 0.1M HCl as a reagent and a flow rate of 2ml/min, a linear calibration up to 25mg/l IO3- with a detection limit of 0.5mg/l IO3- was obtained. Relative standard deviation for 10 injections of 10mg/l IO3- solution was 1.7%. A sample throughput of 35 injections per hour was achieved. The system was successfully applied for determination of iodate in iodized table salts, validating by the AOAC titrimetric method.