Appearance White crystals or crystalline powder Specific rotation[α]20/D (C=1 Acetic acid) +9.3°+ 2° Melting point 159 to 168℃ Heavy metal(Pb) Not more than 20ppm Arsenic (As2O3) Not more than 2ppm Loss on Drying Not more than 0.50% Residue on ignition Not more than 0.30% Assay 98.0% to 102%