Appearance: Slightly yellow crystal powder Almost odorless; Identification: Positive; Solubility: Clear and pale yellow Melting Point: 60~62; Specific rotation: -1.0 to +1.0; Loss on drying: 0.20% max; Residue on Ignition: 0.10% max; Heavy Metals: 10ppm max; Chloride: 0.07% max; Limit of polymer content :2.0% max ; Related substance: Meet the requirements; Assay: 99%~101% Origin China