| ITEM | STANDARD | RESULTS |
| Appearance | white to off-white crystalline powder | Complies |
| Characteristics | UV absorption coefficient :210—227 Melting point:101—105℃ |
210 102.5—103.0℃ |
| Identification | UV: max at 221,243,305nm 10μg/ml(sample/water) HPLC: conforms to standard IR absorption: conforms to standard |
Complies Complies Complies |
| Ph | 6.0—7.5 | 7.0 |
| Related substances | Each impurity substance ≤ 0.5% Total impurity substances ≤ 1.0% |
Complies |
| Loss on drying | ≤0.5% | 0.01% |
| Residue on ignition | ≤0.1% | 0.01% |
| Heavy metals | ≤20ppm | Complies |
| Particle size | 180mesh | 91.2% |
| Assay | ≥98.5% | 99.9% |
| Conclusion | The product complies with WS1-(X-297)-2003Z standard | |
