Appearance: a white to grayish-white crystalline powder Identification: pass Assay: not less than 98.0% Melting point: 157～164℃(dec) Appearance of solution: pass Acidity or alkalinity: pass Related substances: pass Heavy metals: not more than 20ppm Loss on drying: not more than 0.5% Residue on ignition: not more than 0.1% Standards: USP25 Packing: 20g/bag, 2kgs/box CAS No.: 55-31-2