Item Standard Appearance White crystals or crystalline powder Specific rotation[α]20/D (C=10 in 2N HCl) +31.5 to +32.4° 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 0.10% Residue on ignition(sulfated) Not more than 0.10% Assay 99.0% to 100.5% pH 3.0 to 3.5