ITEM | STANDARD |
Appearance | White or almost white crystal or crystalline powder |
Identification | Positive |
Melting point | 191 ℃ ~ 192℃ |
pH (5%, w/v) | 2.2 ~ 2.5 |
pH (2%,w/v) | 2.4 ~ 2.8 |
Specific optical rotation | +20.5° ~ +21.5° |
Clarity of solution | Clear |
Heavy metals | ≤0.0003% |
Assay (as C 6H 8O6, %) | 99.0 ~ 100.5 |
Copper | ≤3 mg/kg |
Iron | ≤2 mg/kg |
Mercury | ≤1 mg/kg |
Arsenic | ≤2 mg/kg |
Lead | ≤2 mg/kg |
Oxalic acid | ≤0.2% |
Loss on drying | ≤0.1% |
Sulphated ash | ≤ 0.1% |
Residual solvents (as methanol) | ≤ 500 mg/kg |
Total plate count (cfu/g) | ≤ 1000 |
Yeasts & molds (cfu/g) | ≤ 100 |
Escherichia. Coli/g | Absence |
Salmonella/ 25g | Absence |
Staphylococcus aureus/ 25g | Absence |