1 | Appearance | White, slightly deliquescent crystals | White, slightly deliquescent crystals or granules. |
2 | Solubility | Passes | Very soluble in water; very slightly soluble in ethanol (96%). |
3 | Identification A (By Chemical test) | Passes | Solution S is faintly acid. |
4 | Identification B (By Chemical test) | Passes | Gives reaction of phosphates |
5 | Identification C (By Chemical test) | Passes | Solution S gives reactions of sodium salt. |
6 | Identification D (By Loss on drying) | 0.3% | Not more than 1.0% |
7 | pH | 4.33 | 4.2 - 4.5 |
8 | Clarity and colour of solution | Passes | Solution S is clear and colourless. |
9 | Arsenic (As) | NMT 2ppm | 2ppm max |
10 | Heavy metals | NMT 10ppm | 10ppm max |
11 | Iron (Fe) | NMT 10ppm | 10ppm max |
12 | Chlorides | NMT 200ppm | 200ppm max |
13 | Sulphate (SO4) | NMT 300ppm | 300pm max |
14 | Reducing substances | Complies | The solution retains a slight red colour. |
15 | Loss on drying,130°C | 0.3% | Not more than 1.0% |
16 | Assay (Dried substance) | 98.59% | 98.0% - 100.5% |