| L-蛋氨酸 | CP2020 | EP11 | USP2023 | USP40 | AJI92 | 
| 含量 | ≥98.5% | 99.0-101.0% | 98.5-101.5% | 98.5-101.5% | 99.0-100.5% | 
| 酸度 | 5.6-6.1 | 5.5-6.5 | 5.6-6.1 | 5.6-6.1 | 5.6-6.1 | 
| 比旋度[a]D20 | +21.0°-+25.0° | +22.5°-+24.0° | / | / | +23.0°-+24.5° | 
| 比旋度[a]D25 | / | / | +22.4°-+24.7° | +22.4°-+24.7° | / | 
| 透光 | ≥98.0% | / | / | / | ≥98.0% | 
| 溶液外观 | / | clear & colorless | / | / | / | 
| 氯化物 | ≤0.02% | ≤0.02% | ≤0.05% | ≤0.03% | ≤0.02% | 
| 铵盐 | ≤0.02% | ≤0.02% | / | ≤0.02% | |
| 硫酸盐 | ≤0.02% | ≤0.03% | ≤0.03% | ≤0.03% | ≤0.02% | 
| 铁盐 | ≤15PPM | ≤10PPM | ≤30PPM | ≤30PPM | ≤10PPM | 
| 重金属 | ≤10PPM | / | / | ≤15PPM | ≤10PPM | 
| 砷盐 | ≤1PPM | / | / | / | ≤1PPM | 
| 其他氨基酸 | ≤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%  | Individual impurities≤0.5%  Total impurities≤2.0%  | conforms | 
| 茚三酮活性物质 | / | / | / | / | / | 
| 干燥失重 | ≤0.2% | ≤0.50% | ≤0.3% | ≤0.3% | ≤0.20% | 
| 炽灼残渣 | ≤0.1% | ≤0.10% | ≤0.4 | ≤0.4 | ≤0.10% | 
| 总菌 | ≤ 1000 CFU/g | ≤ 1000 CFU/g | ≤ 1000 CFU/g | ≤ 1000 CFU/g | ≤ 1000 CFU/g | 
| 霉菌&酵母菌 | ≤ 100 CFU/g | ≤ 100 CFU/g | ≤ 100 CFU/g | ≤ 100 CFU/g | ≤ 100 CFU/g |