APPearance White crystalline powder Specific rotation(a)D20 (C=2,H2O) -11.0º to –12.0º Melting Point (ºC) 158ºC to 161 ºC Chloride(C1) Not more than 0.02% Ammonium(NH4) Not more than 0.02% Sulfate(SO4) Not more than 0.02% Heavy metals(Pb) Not more than 10ppm Iron(Fe) Not more than 10ppm Arsenic(As2O3) Not more than 1 ppm Loss on drying Not more than 0.50% Residue on ignition Not more than 0.1% Assay 98.5-101.0%