| Appearance |
A fine ,amorphous, impalpable, pink or reddish-brown powder
|
Solubility |
Practically completely soluble in mineral acids and insoluble in water
|
| Alkaline substances |
If red colour is produced, NMT 0.2 ml of 0.05M sulphuric acid should be required to decolourise it
|
Water soluble dyes |
The filtrate should be colourless
|
| Ethanol soluble dyes |
The filtrate should be colourless
|
Arsenic (As) |
Max 8.0 ppm
|
| Lead (Pb) |
The solution should remains clear after 5 minutes
|
Calcium (Ca) |
The solution should remains clear
|
| Soluble barium salts |
The solution should remains clear
|
Chlorides |
NMT 750 ppm
|
| Sulphates |
NMT 0.6%
|
Loss on ignition |
Max 2.0% (at 900°C on 2.0 gm of sample)
|
| Microbial contamination |
1 gm should be free from staphylococcus aureus and Pseudomonas aeruginosa
|
Assay (as ZnO; on ignited basis) |
98 - 100.5%
|