| Result | Limits | |
| Assay(by acid-base titrimetry): | 101.8% | ≥99.0% min. |
| Appearance: | White, Crystalline solid | |
| Insoluble in dilute acid: | <0.001% | 0.01% max. |
| pH (5% of Soln. At 20°C): | 4.0 | 4.0-5.0 |
| Water Content(Karl Fischer): | 240 ppm | 500 ppm max. |
| Iron: | 0.0006% | 0.003% max. |
| Sulfate: | <0.01% | 0.05% max. |
| Chloride: | <0.002% | 0.005% max. |
| Heavy Metals (as Pb): | <0.0001% | 0.001% max. |
| Sodium: | 0.002% | 0.05% max. |
| Potassium: | 0.0004% | 0.05% max. |
| Calcium: | 0.001% | 0.03% max. |