Complaint
Vitamin C is a white monoclinic crystal or crystalline powder with melting point on 190 ºC -192 ºC, no smell, sour, yellowish color after long time standing. The product is easily soluble in water, slightly soluble in ethanol, insoluble in ether, chloroform. The aqueous solution is acidic. 5% (W / V) aqueous solution PH2.1-2.6 (W / V), the rotation of aqueous solution is +20.5 ~ +21.5. |
Specification:
| Appearance | White or almost white, crystalline powder or colourless crystals |
| Melting Point | About 190ºC, with decomposition |
| Identification | Positive reaction |
pH (with 5% water solution) | 2.1 ~ 2.6 |
pH (with 2% water solution) | 2.4 ~ 2.8 |
Appearance of solution | Clarity : clear; Colour: ≤BY7 |
Specific optical rotation | +20.5º~ +21.5º |
Loss on drying | ≤0.4% |
Impurity E | ≤0.2% |
Related substance | Impurity C: ≤0.15% Impurity D: ≤0.15% Unspecified impurities: ≤0.10% Total impurities: ≤0.2% |
Copper | ≤5.0ppm |
Iron | ≤2.0ppm |
| Arsenic | ≤3.0ppm |
Lead | ≤2.0ppm |
Mercury | ≤1.0ppm |
Cadmium | ≤1.0ppm |
Heavy metals | ≤10ppm |
Sulphated ash | ≤0.1% |
Residual solvents | Meets the requirement |
Assay | 99.0%~100.5% |
