SPECIFICATION Assay (on dry basis): 98.5% min Specific Rotation [±]20 D: -26.0 degree ~ -29.0 degree Loss on Drying: 1.0% max Residue on Ignition: 0.3% max Ammonium (as NH4+): 0.04% max Heavy Metals (as Pb): 20ppm max Arsenic: 2ppm max Appearance: Off-White Free-Flowing Powder