| Appearance |
White crystalline powder |
| Assay (after ignition) |
99.5-100.5% |
| Identity |
Passes test |
| Appearance of solution |
Passes test |
| Acidity or alkalinity |
Passes test |
| pH (5 % solution) |
5.0 - 8.0 |
| Insoluble matter |
Max 0.005% |
| Bromide (Br) |
Max 0.005% |
| Iodide (I) |
Max 0.001% |
| Ferrocyanide [(Fe(CN)6]4- |
Max 0.0001% |
| Chlorate and nitrate (NO3) |
Max 0.003% |
| Nitrite (NO2) |
Passes test |
| Phosphate (PO4) |
Max 0.0005% |
| Sulphate (SO4) |
Max 0.001% |
| Total nitrogen (N) |
Max 0.0005% |
| Heavy metals (by ICP-OES) |
Max 0.0005% |
| Arsenic (As) |
Max 0.00004% |
| Barium (Ba) |
Max 0.001%(passes test) |
| Calcium (Ca) |
Max 0.002% |
| Copper (Cu) |
Max 0.0002% |
| Iron (Fe) |
Max 0.0002% |
| Magnesium (Mg) |
Max 0.001% |
| Magnesium and alkali earth metals |
Max 0.01% |
| Potassium (K) |
Max 0.005% |
| Loss on drying (at 105°C; 2 hrs) |
Max 0.5% |