| L-半胱氨酸盐酸盐 | CP2020 | EP11 | USP2023 | 
| 含量 | ≥98.5% | 98.5-101.0% | 98.5-101.5% | 
| 酸度 | 1.5-2.0 | / | / | 
| 比旋度[a]D20 | +5.5°-+7.0° | +5.5°-+7.0° | / | 
| 比旋度[a]D25 | / | / | +5.7°-+6.8° | 
| 透光 | ≥98.0% | / | / | 
| 溶液外观 | / | clear & colorless ≤BY6 | / | 
| 氯化物 | 19.8-20.8% | / | |
| 铵盐 | / | ≤0.02% | / | 
| 硫酸盐 | ≤0.02% | ≤0.03% | ≤0.03% | 
| 铁盐 | ≤10PPM | ≤20PPM | ≤30PPM | 
| 重金属 | ≤10PPM | / | / | 
| 砷盐 | ≤1PPM | / | / | 
| 其他氨基酸 | ≤0.5% | / | individual impurities≤0.5%  total impurities≤2.0%  | 
| 茚三酮活性物质 | / | Each impurity≤ 0.2% Total impurity≤ 1.0%  | / | 
| 干燥失重 | 8.0-12.0% | 8.0-12.0% | 8.0-12.0% | 
| 炽灼残渣 | ≤0.10% | ≤0.10% | ≤0.4% | 
| 内毒素 | conform | conform | conform | 
| 总菌 | ≤ 500 CFU/g | ≤ 500 CFU/g | ≤ 500 CFU/g | 
| 霉菌&酵母菌 | ≤ 50 CFU/g | ≤ 50 CFU/g | ≤ 50 CFU/g |