| 1 | Appearance/Description | Colorless, translucent fine crystalline powder. | Colorless, translucent crystals; white or almost white granular to fine crystalline powder. (Note: The product may cause lumps or hardening over the storage). | USP/Ph.Eur |
| 2 | Solubility | Complies | Very soluble in water, Freely soluble alcohol, freely soluble in ethanol (96%),very slightly soluble in ether. | USP/Ph.Eur |
| 3 | Melting point | 154°C | About 153°C, with decomposition. | Ph.Eur |
| 4 | Identification (By IR) | Complies | IR spectra of the sample should be concomitant with IR spectra of standard | USP/Ph.Eur |
| 5 | Identification (By chemical test 1) | Complies | The solution should be strongly acidic. | Ph.Eur |
| 6 | Identification (By chemical test 2) | Complies | A red colour should develop. | Ph.Eur |
| 7 | Identification (By chemical test 3) | Complies | A white precipitate should form. | Ph.Eur |
| 8 | Identification (By Water) | 0.074% | NMT 1.0% | Ph.Eur |
| 9 | Appearance of Solution | Complies | The solution should be clear and colourless or not more intensely coloured than reference solution Y7, BY7 or GY7. | Ph.Eur |
| 10 | Clarity of solution | Complies | The sample solution should show the same clarity as that of water or its opalescence is not more pronounced than standard suspension. | USP |
| 11 | Colour of solution | Complies | The sample solution should not more intensely colored than standard solutions | USP |
| 12 | Readily carbonizable substances | Complies | The solution should not be more intensely coloured than reference standard | USP/Ph.Eur |
| 13 | Oxalic acid | Less than 360 ppm | NMT 360ppm | USP/Ph.Eur |
| 14 | Sulfates | Less than 150 ppm | NMT 150ppm | USP/Ph.Eur |
| 15 | Water | 0.074% | NMT 1.0% | USP/Ph.Eur |
| 16 | Sulphated ash / Residue on ignition | 0.023% | NMT 0.1% | USP/Ph.Eur |
| 17 | Assay (Anhydrous basis) | 100.35% | 99.5%-100.5% | USP/Ph.Eur |
| 18 | Particle size | 98.54% material passes through #40 mesh | NLT 50% material should pass through #40 mesh”. | In-house |