Determination of trace amounts of iodine by inhibition kinetic spectrophotometry

A simple and sensitive kinetic spetrophotometric method for determination of trace iodine has been developed.The method is based on the inhibition effect of iodine on the fading reaction in which nitrite catalyzes potassium bromate to oxidize methylene blue in dilute phosphoric acid medium.The linear range of determination is 0.040-0.48 μg/mL.The detection limit is 1.7×10~(-8) g/mL.The method has been used for the determination of trace iodine in salt sample with satisfactory results.