SPECTROPHOTOMETRIC DETERMINATION OF RUTHENIUM WITH 2 4 6-TRI(2'-PYRIDYL)-S-TRIAZINE

Ruthemum(III) reacts with 2,4,6-tri(2′-pyridyl)-s-triazine (TPTZ) in water-alcohol solution at pH 2.2 to 4.0 to give a red-purple solution having an absorption peak at 510 mμ. Full color development requires heating at 87 °C. for one hour; the color is stable for more than 12 hours. The system conforms to Beer'fs law; optimum range for measurement at 1.00-cm optical path is about 1 to 4 ppm of ruthenium. Common anions do not interfere; separation from interfering cations is effected by distillation and recovery of ruthenium tetroxide. A reaction ratio of ruthenium-to-TPTZ of 1-to-2 is shown by the methods of continuous variations and mole ratio. Isolation and elemental analysis of the picrate and the perchlorate of the cationic complex confirm the 1-to-2 reaction ratio. © 1968, American Chemical Society. All rights reserved.