| 1 | Appearance | Colourless crystals | White or almost white, crystalline powder, colourless crystals or granules. |
| 2 | Solubility | Complies | Very soluble in water, freely soluble in ethanol (96%) |
| 3 | Melting point | 152°C | About 153°C, with decomposition. |
| 4 | Identification A (By Chemical test) | Complies | The solution should be strongly acidic. |
| 5 | Identification B (By IR) | Complies | IR spectra of the sample should be concomitant with IR spectra of standard |
| 6 | Identification C (By Chemical test) | Complies | A red color should develop. |
| 7 | Identification D (By Chemical test) | Complies | A white precipitate should form. |
| 8 | Identification E (By Water) | 0.06% | 1.0% max |
| 9 | Appearance of Solution | Complies | The solution should be clear and colorless or not more intensely colored than reference solution Y7, BY7 or GY7. |
| 10 | Readily carbonizable substances | Complies | The solution should not be more intensely colored than a mixture of 1ml of red primary solution and 9ml of yellow primary solution. |
| 11 | Oxalic acid | Less than 360ppm | 360ppm max. |
| 12 | Sulfates | Less than 150ppm | 150ppm max |
| 13 | Water | 0.06% | 1.0% max |
| 14 | Sulphated ash | 0.03% | 0.1% max |
| 15 | Assay (Anhydrous basis) | 99.8% | 99.5%-100.5% |