Appearance White crystals or crystalline powder Specific rotation[α]20/D (C=2,H2O) +14.0°to+17.0° Transmittance Not less than 95.0% Heavy metal(Pb) Not more than 20ppm Iron (Fe) Not more than 10ppm Sulfate (SO4) Not more than 0.10% Loss on drying Not more than 0.50% Residue on ignition Not more than 0.30% Assay 98.0to102.0%