Molecular Formula: C5H11NO2S
Molecular Weight: 149.21
CAS No: 63-68-3
| L-Methionine | CP2020 | EP11 | USP2023 |
| Assay | ≥98.5% | 99.0-101.0% | 98.5-101.5% |
| PH | 5.6-6.1 | 5.5-6.5 | 5.6-6.1 |
| Specific rotation[a]D20 | +21.0°-+25.0° | +22.5°-+24.0° | / |
| Specific rotation[a]D25 | / | / | +22.4°-+24.7° |
| Transmittance(T430) | ≥98.0% | / | / |
| Appearance of solution | / | clear & colorless | / |
| Chloride(Cl) | ≤0.02% | ≤0.02% | ≤0.05% |
| Ammonium(NH4) | ≤0.02% | ≤0.02% | |
| Sulfate(SO4) | ≤0.02% | ≤0.03% | ≤0.03% |
| Iron(Fe) | ≤15PPM | ≤10PPM | ≤30PPM |
| Heavy metals(Pb) | ≤10PPM | / | / |
| Arsenic | ≤1PPM | / | / |
| Other amino acids | ≤0.5% | Each impurity≤ 0.1% Total impurities≤ 0.3% | Methionine sulfoxide≤0.1% N-Acetyl-D,L-methionine≤0.2% Any unspecified impurity≤0.1% Total unspecified impurities≤0.3% |
| Ninhydrin-positive substances | / | / | / |
| Loss on drying | ≤0.2% | ≤0.50% | ≤0.3% |
| Residue on ignition | ≤0.1% | ≤0.10% | ≤0.4 |
| Endotoxin | <25 EU/g | <25 EU/g | <25 EU/g |
| Total plate count | ≤ 500 CFU/g | ≤ 500 CFU/g | ≤ 500 CFU/g |
| Moulds & Yeasts | ≤ 50 CFU/g | ≤ 50 CFU/g | ≤ 50 CFU/g |