Appearance White crystals or crystalline powder Specific rotation[α]20/D (C=8 in 6N HCl) +24.0ºto +26.5 º Ammonium (NH4) Not more than 0.02% Sulfate (SO4) Not more than 0.030% Iron (Fe) Not more than 30ppm 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 0.5% Residue on ignition(sulfated) Not more than 0.20% Assay 98.0% to 101.0% pH 5.0 to 7.0