1 | Appearance/Description | White crystalline powder. Its solutions are acid to litmus and effervesce with sodium carbonate. | Colorless crystals or a white crystalline powder. Its solutions are acid to litmus and effervesce with sodium carbonate. |
2 | Solubility | Complies | Very soluble in water; very slightly soluble in ethanol (96%). practically insoluble in alcohol. |
3 | Identification (By chemical test) | Complies | Solution should be slightly acid. |
4 | Identification (Phosphate 1) | Complies | A neutral solution should yield yellow precipitate with silver nitrate solution that soluble in 2N nitric acid and 6 N ammonium hydroxide. |
5 | Identification (Phosphate 2) | Complies | With ammonium molybdate solution, acidified solutions should yield a yellow precipitate with ammonium molybdate solution which should soluble in 6N ammonium hydroxide. |
6 | Identification (Sodium) | Complies | A dense precipitate should form. |
7 | Identification D (By Loss on drying) | 12.9% | 11.5% - 14.5% |
8 | Acidity / PH | 4.28 | pH of the solution should be between 4.2 and 4.5 |
9 | Clarity and colour of solution | Complies | Clear and colorless solution |
10 | Arsenic (As) | Less than 2ppm | NMT 2ppm |
11 | Iron (Fe) | Less than 10ppm | NMT 10ppm |
12 | Sulphate (SO4) | Less than 300ppm | NMT 300pm |
13 | Chloride (Cl) | Less than 0.014% | NMT 0.014% |
14 | Reducing substances | Complies | The solution retains a slight red color. |
15 | Loss on drying at 130°C | 12.9% | 11.5% - 14.5% |
16 | Water | 11.3% | 10.0% - 15.0% |
17 | Assay (Dried substance) | 99.1% | 98.0% - 100.5% |
18 | Assay (Anhydrous basis) | 99.1% | 98.0% - 103.0% |
19 | Insoluble Substances | 0.004% | NMT 0.2% |
20 | Aluminium, Calcium and Related Element | Complies | The sample solution should not become turbid when rendered slightly alkaline to litmus paper with 6N ammonium hydroxide. |