|
Appearance
|
White crystals
|
|
Assay (alkalimetric; on dried basis)
|
99.5-100.5%
|
|
Identification
|
To comply IP, BP, USP tests
|
|
Solubility
|
Soluble in water and in ethanol (96 per cent), freely soluble in boiling water and in glycerol (85 per cent)
|
|
Appearance of solution
|
To comply IP, BP, USP
|
|
Substance insoluble in alcohol
|
To comply IP, BP, USP test
|
|
pH (3.3% solution in water)
|
3.8-4.8
|
|
Sulphate (SO4)
|
Max 0.045%
|
|
Heavy metal (as Pb)
|
max 0.0015%
|
|
Arsenic (As)
|
max 0.001%
|
|
Organic impurities
|
To comply BP test
|
|
Loss on drying (5hrs; over silica gel)
|
Max 0.5%
|