Analytical Sciences

Abstract − Analytical Sciences, 18(6), 667 (2002).

Sensitive Kinetic-Spectrophotometric Determination of Iodate in Iodized Table Salt Based on Its Accelerating Effect on the Reaction of Bromate with Chloride Ion in the Presence of Hydrazine
Abbas AFKHAMI  and Fatemeh MOSAED
Department of Chemistry, Faculty of Sciences, Bu-Ali Sina University, Hamadan, Iran
A simple, precise, sensitive and accurate method was developed for rapid determination of trace quantities of iodate. The method is based on the accelerating effect of iodate on the reaction of bromate and chloride acid in the presence of hydrazine in acidic media. The decolorization of Methyl Orange with the reaction products was used to monitor the reaction spectrophotometrically at 525 nm. Iodate could be determined in the concentration ranges of 0.03 - 1.2 ug ml-1. The relative standard deviation for ten replicate determinations of 0.3 ug ml-1 of iodate was 1.65%. The proposed method was applied to the determination of iodate in table salts with satisfactory results.