Selective determination of trace amounts of iron by a kinetic fluorimetric method

Abstract

The coupled catalysis of iron(III) and vanadium(V) in the autoxidation of sodium 4,8-diamino-1,5-dihydroxyanthraquinone-2,6-disulphonate (DADHADS) is discussed. The reaction is followed by measuring the rate of appearance of the intensely fluorescent oxidation product, and the initial rate method is applied to determine trace amounts of iron(III). The sensitivity and selectivity of the method have been studied. Iron contents between 0.06 and 1.0 µg ml^–1 have been determined with a relative standard deviation of 5.8% and a detection limit of 18 ng ml^–1.