| ITEM | STANDARD | RESULTS |
| Appearance | White or off-white powder | Comply |
| Identification | IR, UV | Comply |
| Solubility | Very slightly or slightly soluble in water, Freely soluble in anhydrous ethanol and methanol, slightly soluble in acetone |
Comply |
| Assay | 99~101% (Titration) | 99.71% |
| Related Substances Impurity B Impurity E Single unknown impurity Total impurities |
≤0.15% ≤0.05% ≤0.05% ≤0.30% |
0.010% Comply 0.040% 0.074% |
| Loss on drying | ≤0.5% | 0.02% |
| Heavy metals | ≤20ppm | Comply |
| PH | 3.0~4.5 | 3.62 |
| Residue on ignition | ≤0.1% | 0.04% |
| Storage | Keep tightly closed. Store in a cool dry place | |
