Simultaneous spectrophotometry of Fe2+ and Cu2+ in serum denatured with guanidine hydrochloride.

We show how iron and copper ions may be simultaneously measured in 0.2 ml of serum after using guanidine hydrochloride to cause their release from protein. Sensitive reagents for iron (2,4,6-tripyridyl-s-triazine) and copper (disodium 2,9-dimethyl-4,7-diphenyl-1, 10-phenanthroline disulfonate) facilitate such measurement. We eliminated spectral interference between the two metal-ion complexes by selective use of pH. Results compare well with those obtained by accepted methods in which the concentrations of these ions are measured independently.