| Description | USP |
|---|---|
| Limit of Calcium | Not more than 1.5% |
| Heavy Metals | Not more than 5 ppm |
| Limit lead | Not more than 0.00015% |
| Microbial Limits | Absence of Escherichia coli |
| Soluble Alkalies | Not more than 1 ml |
| Soluble Salt | Not more than 12 mg |
| Carbonate and Acid-insoluble Matter | Not more than a slight effervescence occurs, and the solution is not more than slightly turbid. |
| Assay | Not less than 29.0% and not more than 33.0% |