|
Appearance
|
Colorless crystals or white crystalline powder
|
|
Assay
|
99.0 - 100.5%
|
|
Identity (acc. to pharmacopoeias)
|
Passes test
|
|
Appearance of solution
|
Passes test
|
|
Insoluble matter in water
|
Max 0.01%
|
|
pH (1% solution in water)
|
4.1-4.7
|
|
pH (5% solution in water; 20°C)
|
4.2-4.5
|
|
pH (5.7% solution in water)
|
4.1-4.5
|
|
Chloride (Cl)
|
Max 0.001%
|
|
Sulphate (SO4)
|
Max 0.005%
|
|
Aluminium, calcium and related elements
|
Passes test
|
|
Substance reducing KMnO4 (as O)
|
Passes test
|
|
Arsenic (As)
|
Max 0.0002%
|
|
Calcium (Ca)
|
Max 0.002%
|
|
Iron (Fe)
|
Max 0.001%
|
|
Heavy metal (as Pb)
|
Max 0.0005%
|
|
Magnesium (Mg)
|
Max 0.001%
|
|
Potassium (K)
|
Max 0.005%
|
|
Loss on drying (at 130°C)
|
21.5 - 24.0%
|