| Tests | Specification |
| Appearance | White crystal |
| Melting point | 150ºC~155ºC |
| Identification | IR should matches reference |
| 260nm Ultraviolet absorbance(1M aq.) | ≤ 0.06% |
| 280nm Ultraviolet absorbance(1M aq.) | ≤ 0.05% |
| 290nm Ultraviolet absorbance(1M aq.) | ≤ 0.05% |
| PH(5% aq.) | 4.2~5.0 |
| Heavy Metals | ≤5 ppm |
| Ferric ion | ≤5 ppm |
| Loss on drying | ≤0.5% |
| Assay | 99.0 ~ 101.0% |