1 | Appearance | White powder. | White or almost white powder. |
2 | Solubility | Complies | Freely soluble in water, very slightly soluble in ethanol(96%) |
3 | Identification A (By Chemical test) | Complies | Solution should slightly alkaline. |
4 | Identification B (sulfate) | Complies | A white precipitate should form. |
5 | Identification C (Sodium) | Complies | A dense white precipitate should form. |
6 | Identification D (By Assay) | 97.5% | 95.0% to 100.5% |
7 | Appearance of solution | Complies | Clear and colourless solution. |
8 | Thiosulphate(S2O3) | Less than 0.1% | NMT 0.1% |
9 | Iron(Fe) | Less than 10ppm | NMT 10ppm |
10 | Zinc (Zn) | 1ppm | NMT 25ppm |
11 | Assay | 97.5% | 95.0% to 100.5% |