| 1 | Appearance/Description | Colourless, translucent crystals | Colourless, translucent crystals or white or almost white granular to fine crystalline powder, efflorescent.(Note: The product may cause lumps or hardening over the storage). | USP/Ph.Eur/BP |
| 2 | Solubility | Complies | Very soluble in water, freely soluble in alcohol and ethanol(96%), very slightly soluble in ether, | USP/Ph.Eur/BP |
| 3 | Identification (By chemical test 1) | Complies | The solution should be strongly acidic. | Ph.Eur/BP |
| 4 | Identification (By IR) | Complies | IR spectra of the sample should be concomitant with IR spectra of the corresponding standadrd | USP/Ph.Eur/BP |
| 5 | Identification (By chemical test 2) | Complies | A red colour should develop. | Ph.Eur/BP |
| 6 | Identification (By chemical test 3) | Complies | A white precipitate should form. | Ph.Eur/BP |
| 7 | Identification (By Water) | 7.68% | 7.5% to 9.0% | Ph.Eur/BP |
| 8 | Appearance of Solution | Complies | The solution is clear and colourless or not more intensely coloured than reference solutions | Ph.Eur/BP |
| 9 | Clarity of solution | Complies | The sample solution shows the same clarity as that of water or its opalescence should not more pronounced than standard suspension A | USP |
| 10 | Colour of solution | Complies | The sample solution should not be more intensely colored than water or standard solutions | USP |
| 11 | Assay (anhydrous basis) | 99.85% | 99.5%-100.5% | USP/Ph.Eur/BP |
| 12 | Residue on ignition /Sulfated ash | 0.017% | NMT 0.1% | USP/Ph.Eur/BP |
| 13 | Sulphate (SO4) | Less than 0.015% | NMT 0.015% (NMT 150 ppm) | USP/Ph.Eur/BP |
| 14 | Oxalic acid | Less than 0.036% | NMT 0.036% (NMT 360 ppm) | USP/Ph.Eur/BP |
| 15 | Readily carbonizable substances | Complies | The color of the acid should not be darker than that of a similar volume of reference standards | USP/Ph.Eur/BP |
| 16 | Water | 7.68% | 7.5% to 9.0% | USP/Ph.Eur/BP |
| 17 | Bacterial endotoxin test | Less than 0.5 EU/mg | NMT 0.5 EU/mg | In-house |