Assay (alcalimetric, calculated on anhydrous substance): ≥ 99.5 %
Identity (IR-spectrum): passes test
Melting point: about 215 °C, with decomposition
Substances insoluble in water: passes test
Sulfated ash: ≤ 0.2 %
Water (according to Karl Fischer): 7.0 - 8.5 %
Suitability as indicator: passes test
Sensitivity test (at Iron II ions): passes test




