Spectrophotometric determination of periodate and iodate by a differentialkinetic method

A rapid, simple and sensitive differential kinetic method is presented for the determinations of periodate and iodate ions. The method is based on the ir reaction with iodide in the presence of methylene blue. The reactions ca n be monitored spectrophotometrically by measuring the decrease in absorban ce at 665 nm. Two sets of conditions were established that in one set of co nditions only periodate reacted with iodide but in the other set both the i ons reacted with iodide during the first 180 s after initiation of the reac tion. The data were evaluated by proportional equations. The method allowed the determination of periodate and iodate at concentrations between 0.1 an d 1.0 and 0.1 and 1.3 118 ml(-1), respectively. The method was applied to C he determination of periodate and iodate in tap watts and spring water with satisfactory results. (C) 2001 Elsevier Science B.V. All rights reserved.