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

A very simple flow injection amperometric system for determination of iodat e has been developed. Cyclic voltammetry was used to study reactions of iod ate, iodide and iodine on a glassy carbon electrode. A single line manifold of the dow system consists of a pulse-free reagent propulsion using a simp le Mariotte bottle, a home-made injection valve, and a cross flow electroch emical cell with a potentiostat for control a potential of glassy carbon wo rking electrode at +200 mV versus Ag/AgCl electrode. Using a solution of 1. 0% w/v NaCl, 0.02% w/v KI and 0.1 M HCl as a reagent and a flow rate of 2 m l/min, a linear calibration up to 25 mg/l IO3- with a detection limit of 0. 5 mg/l IO3- was obtained. Relative standard deviation for 10 injections of 10 mg/l IO3- solution was 1.7%. A sample throughput of 35 injections per ho ur was achieved. The system was successfully applied for determination of i odate in iodized table salts, validating by the AOAC titrimetric method. (C ) 2001 Elsevier Science B.V. All rights reserved.