Assay Not less than 98.5% Specific rotation -196º to –205º Iron(Fe) Not more than 10ppm Loss on Drying Not more than 0.50% Ammonium (NH4) Not more than 0.02% Other amino acid Chromatographically not detectable Sulfate (SO4) Not more than 0.030% Residue on ignition (sulfated) Not more than 0.20% Heavy metal(Pb) Not more than 10ppm Arsenic(As2O3) Not more than 1ppm