Abstract
A study was carried out on the determination of iron using the formation of an iron(III)-diantipyrylmethane complex and a new spectrophotometric procedure was proposed, which was applied to the determination of iron in cements as an example.
An iron(III)-diantipyrylmethane complex is formed in a slightly or weakly acidic medium (the optimum acidity: pH 2.03.5) and has an absorption maximum at 450 mμ. The complex formation is instantaneous at room temperature and the color is very stable. A linear relationship was maintained between the concentration of iron and the absorbance. The molar extinction coefficient and the sensitivity for log(I0/I) = 0.001 under the recommended conditions were 5400 and 1.0 × 10-2 μgFe/cm2, respectively. Several ions including molybdenum, tungsten, lead, perchlorate, phosphate, etc. interfered with the determination. Satisfactory results were obtained in the determination of iron in cements.
