Spectrophotometric determination of iron(III) ions with 2,4-dihydroxybutyrophenone

Abstract

The colour reaction between iron(III) and 2,4-dihydroxybutyrophenone has been studied to determine the optimum conditions for the analytical use of this reagent. The strongest colour developed at pH 2·9 to 3·0, and the complex exhibits an absorption maximum at 470 m µ. The composition of the complex is 1 to 1, as indicated by mole-ratio studies. The absorbance of the solution at 470 m µ obeys Beer's Law in the iron(III) concentration range 1·0 to 56·0 p.p.m. and the sensitivity is 0·074 µg per ml of the iron(III) solutions. The reagent is fairly selective for iron.