Application of ternary complexes in pharmaceutical analysis. IV--Spectrophotometric determination of iron (II) in anti-anaemic formulations, using as chelating ligands in micellar medium three newly developed hydrazones.

The preparation, structural and physicochemical characterisation of three new hydrazones of isoniazid with 2,3-dihydroxy-,3,4-dihydroxy- and 2,3,4-tri-hydroxybenzaldehyde are described. The formation of binary chelates of iron(III) with these hydrazones and ternary complexes with the hydrazones and various surfactants were studied including the optimization of the experimental conditions. The new reagents were successfully used for the spectrophotometric determination of iron(II) in anti-anaemic formulations after its oxidation with hydrogen peroxide to iron(III). The statistical comparison of the results obtained with the new reagents and with the classical o-phenanthroline method is presented.