1 | Appearance | Almost white crystalline powder. | White or almost white to yellowish crystalline powder or colorless crystals. |
2 | Solubility | Complies | Freely soluble in water. Slightly soluble in ethanol (96%) and alcohol. |
3 | Identification A (By pH) | 4.15 | 3.5 to 5.0 |
4 | Identification (Reaction of sulfates) | Complies | White precipitate should form. |
5 | Identification (Reaction of sodium) | Complies | A dense white precipitate should form. |
6 | Identification (Sulfite) | Complies | A filter paper moistened with mercurous nitrate solution should blacken. |
7 | Appearance of solution | Complies | Clear and colorless solution. |
8 | pH | 4.15 | 3.5 to 5.0 |
9 | Limit of Thiosulfate | Less than 0.05% | NMT 0.05% |
10 | Arsenic (As) | Less than 0.0001% | NMT 0.0001% |
11 | Heavy metals | Less than 20ppm | NMT 20ppm |
12 | Iron (Fe) | Less than 20ppm | NMT 20ppm (0.002%) |
13 | Limit of Chloride | Less than 0.05% | NMT 0.05% |
14 | Assay(as SO2) | 65.1% | 65.0%- 67.4% |
15 | Assay | 96.6% | 95.0% - 100.5% |
16 | Total aerobic microbial count | Less than 100 CFU/gm | NMT 100 CFU/gm |
17 | Total Yeast and mold count | Less than 10 CFU/gm | NMT 10 CFU/gm |
18 | E.coli | Absent/gm | should be absent/gm |
19 | Salmonella | Absent/10gm | should be absent/10gm |
20 | Pseud. aeruginosa | Absent/gm | should be absent/gm |
21 | Staphylococcus aureus | Absent/gm | should be absent/gm |
22 | Bile-tolerant gram negative bacteria | Absent/gm | should be absent/gm |
23 | Bacterial endotoxin test | Less than 6.0 EU/gm | NMT 6.0 EU/gm |