Complaint
| Items | Standard | Result |
| Appearance | Small colourless crystals or shiny flakes or white crystalline powder | Conforms |
| Heavy metal | ≤0.002% | <0.002% |
| Water | ≤0.5 | 0.19% |
| Sulfite or thiosulfate | ≤0.15ml | <0.15ml |
| Assay | 99.5%100.5% | 99.7% |
| Conclusion | The sample meets the specification of USP32 | |
Items | Standard | Result |
Appearance | White to off-white powder | White powder |
Assay (W/W dry basis) | ≥98.0% | 99.16 % |
Residue on ignition | <0.5% | 0.256% |
Water (w/w by KF) | ≤1.0% | 0.420% |
pH Value(1% aq.) | 5~9 | 7.28 |
