|Appearance||white crystalline powder|
|Heavy metals||10ppm max|
|Other amino acids||not detectable|
|Loss on drying||0.50% max|
|Residue on ignition||0.10% max|
|Storage||2 years in seal and shading place|
L-Cysteine hydrochloride 52-89-1 is an important source of sulfide in human metabolism. The sulfide in iron-sulfur clusters and in nitrogenase is extracted from cysteine, which is converted to alanine in the process.