Items

EP standard

CP standard

USP standard

AJI standard

Assay

≥99.0%

≥99.0%

≥98.5%

≥99.0%

Specific rotation

-30.0°— -32.5°

-30.0°— -32.5°

-29.4°—-32.8°

-30.5°— -32.5°

PH value

5.6-6.2

5.4-6.4

5.5－7.0

5.6-6.2

Light transmittance

≥97.0%

≥97.0%

——

≥95.0%

Chloride

≤0.02%

≤0.02%

 ≤0.05%

≤0.02%

Sulfate

≤0.02%

≤0.02%

≤0.03%

≤0.02%

Ammonium

≤0.02%

≤0.02%

——

≤0.02%

Other amino acids

Comply with the standard

Comply with the standard

——

Comply with the standard

Loss on drying

≤0.2%

≤0.2%

≤0.3%

≤0.2%

Residue on ignition

≤0.1%

≤0.1%

≤0.1%

≤0.1%

Iron

≤0.002%

≤0.002%

≤0.003%

≤0.002%

Heavy metals

≤0.001%

≤0.001%

≤0.0015%

≤0.001%

Arsenic

≤0.0001%

≤0.0001%

——

≤0.0001%

Bacterial endotoxin

The amount of bacterial endotoxin in every 1g of this product should be less than 12.5EU

The amount of bacterial endotoxin in every 1g of this product should be less than 12.5EU

——

——

Sum of impurities with a retention time less than that of tryptophan

≤100ppm

——

——

——

Sum of impurities with a retention time greater than that of tryptophan

≤300ppm

——

——

——

N-acetyltryptophan

  Not detectale

——

——

——

Impurity A

≤10ppm

——

——

——