DETERMINATION OF IRON IN GLASS SAND*

The 0-phenanthroline method for the colorimetric determination of iron has been adapted to the analysis of glass sand. The sample taken for analysis was decomposed by treatment with HF and H₂SO₄, followed by fusions of any insoluble material with Na₂CO₃ and finally with K₂S₂O₇. An aliquot was then adjusted to the proper pH by a simple procedure, the iron reduced by hydroxylamine hydrochloride, the 0-phenanthroline complex formed, and the transmittancy of the solution measured spectrophotometrically. The method is simple and rapid, and compares favorably in precision and accuracy with other available methods.