Determination of serum iron and the total iron-binding capacity with a new chromogen, 4-aminophenazone

A colorimetric procedure is described for the determination of serum iron and TIBC, utilizing the action of the iron on the oxidation reaction of 4-aminophenazone with H2O2. The chromogen oxidized has maximum absorption at 540 nm. The method is interesting because it has important advantages over other methods: no deproteinization is needed, microsamples are used, it is simple, gives adequate precision, and the results correlate well with those obtained with the standard bathophenanthroline method.