L-leucine   

Appearance White crystals or crystalline powder Specific rotation[α]20/D (C=4 in 6N HCl) +14.9 to +16.0° State of solution (Transmittance) Clear and colorless Not less than 98.0% Chloride (Cl) Not more than 0.020% Ammonium (NH4) Not more than 0.02% Sulfate (SO4) Not more than 0.020% Iron (Fe) Not more than 10ppm Heavy metal(Pb) Not more than 10ppm Arsenic(As2O3) Not more than 1ppm Other amino acids Chromatographically Not detectable Loss on drying Not more than 0.20% Residue on ignition(sulfated) Not more than 0.10% Assay 98.5 to100.5% pH 5.5 to 6.5