Item | USP24 | USP38 | EP8 |
Assay | 98.5-101.5% | 98.5-101.5% | 98.5-101.0% |
PH | 5.5-7.0 | 5.5-7.0 | --- |
Specific rotation[a]D20 | --- | --- | +40.0-+43.0 |
Specific rotation[a]D25 | +38.9°-+41.8° | +38.9°-+41.8° | --- |
Transmittance(T430) | --- | --- | clear & colorless ≤BY6 |
Chloride(Cl) | ≤0.05% | ≤0.05% | ≤0.02% |
Ammonium(NH4) | --- | --- | --- |
Sulfate(SO4) | ≤0.03% | ≤0.03% | ≤0.03% |
Iron(Fe) | ≤30PPM | ≤30PPM | ≤10PPM |
Heavy metals(Pb) | ≤15PPM | ≤15PPM | ≤10PPM |
Other amino acids | --- | individual impurities≤0.5% total impurities≤2.0% | --- |
Ninhydrin-positive substances | --- | --- | conform |
Loss on drying | ≤0.30% | ≤0.30% | ≤0.5% |
Residue on ignition | ≤0.30% | ≤0.30% | ≤0.10% |
Organic volatile impurities | conforms | --- | --- |