Volumetric Determination of Iodides by Ceric Sulfate: An Application of the Indicator [i]o[/i]-Phenanthroline Ferrous Ion

Abstract

ANALYTICAL EDITION199 assumption was made that each mole of peroxide reacted with two equivalents of ferrous sulfate. The comparison of the two methods is presented in Table I, the results being reported in terms of gram equivalents of active oxygen per liter of hydrocarbon.The lower results given by the method of Yule and Wilson are probably due to the incomplete reduction of the peroxides, for the reacting substances are, on the whole, concentrated in two different layers. The more peroxide there is present, the more difficult it becomes to obtain a quantitative reduction. Yule and Wilson have noted that an increase in peroxide concentration does not give a proportionate increase in the quantity of peroxide detected by their method.

Ceric Salts in Volumetric Analysis

“…The iodine liberated reacts with acetone to form iodoacetone. The method is stated to be accurate in the presence of limited amounts of bromide or chloride ion (82). Iodine in thyroid has been determined by titration of the iodide in hydrochloric acid solution with ceric sulfate, either with ferroin as indicator or with chloroform to detect the iodine monochloride end point (32,61).…”