| Item | Specifications | Results |
| Appearance | White crystalline powder | White crystalline powder |
| Purity | 98.5~101.0% | 99.8% |
| PH | 2.85-3.60 | 3.52 |
| Histidine（TLC） | Not be detected | Passed |
| Solubility | Clearly | Passed |
| Loss on drying | ≤0.50% | 0.25% |
| As | ≤10ppm | 6ppm |
| SO4 | ≤0.02% | 0.015% |
| Pb | ≤10ppm | 7ppm |