| Items | Specifications |
| Appearance | White crystal or crystalline powder |
| Assay (dry Basis, %) | 99.5—101.0% |
| Initial melting point | 158.0—161.0°C |
| Loss on drying | 0.50% max |
| Heavy metals | 20ppm max |
| Chloride | 0.014% max |
| Residue on ignition | 0.05% max |
| Related compound | 0.20% max |
| Sulphate | 0.02% max |
