Appearance: Colorless and rhombic crystals Assay: 99.7% min. Specific rotatory power [a]D25 : +12.0°~+13.0° Loss on drying : 0.5 % max Residue on ignition : 0.05% max Sulfate(SO4) : qualified Oxalate : qualified Arsenic(As) : Max. 3 mg/kg Heavy metal : Max. 10 mg/kg Lead: ＜ 2 mg/kg