1 | Appearance | Colorless crystals. | A white or almost white powder or colourless crystals. |
2 | Solubility | Complies | Very soluble in water, very slightly soluble in ethanol (96%) |
3 | Identification A (By Chemical test) | Complies | Solution should be slightly acid |
4 | Identification B1 (Phosphate) | Complies | A yellow precipitate should form which colour does not changes by boiling and which dissolves on addition of ammonia. |
5 | Identification B2 (Phosphate) | Complies | A yellow color should develop |
6 | Identification C (for Sodium) | Complies | A dense white precipitate should form |
7 | Appearance of solution | Complies | Clear and colorless solution |
8 | pH | 4.3 | 4.2 - 4.5 |
9 | Reducing substances | Complies | The color of permanganate should not completely discharge |
10 | Chlorides | Less than 200ppm | NMT 200ppm |
11 | Sulphate (SO4) | Less than 300ppm | NMT 300ppm |
12 | Arsenic (As) | Less than 2ppm | NMT 2ppm |
13 | Iron (Fe) | Less than 10ppm | NMT 10ppm |
14 | Loss on drying,130°C | 23.3% | 21.5% - 24.0% |
15 | Assay (on dried basis) | 98.7% | 98.0% - 100.5% |