Determination of Trace Iron by Catalytic Kinetic Spectrophotometry

Based on the catalytic effect of ferrous ion in the oxydizing decolouration of methylene blue by hydrogen peroxide in a medium of pH=7 0, a new catalytic kinetic method is proposed for the determination of trace iron. The optimum conditions of the method has been obtained. The detection limit and the linear range are 7 91×10 -7 and 0～1 5 μg/(25 mL) respectively. The method has been applied to the determination of trace iron in water and flour with satisfactory results.