Inspection Items | USP requirement |
Appearance | Fluffy, white powder |
Viscosity(mPa·s) (0.5%W/V) | 40000-60000 |
PH value | 2.5-3.5 |
Loss on drying (%): | ≤2.0 |
Residue on ignition (%): | ≤2.0 |
Heavy metal(ppm): (Pb, As, Hg, Sb) | ≤20 |
Carboxylic acid groups(%) : | 56.0-68.0 |