Appearance:White crystalline powder or granular Assay (on dry basis):99.0% 101.0% Loss on drying;no more than 0.2% Ash:no more than 0.01% Melting range:118centi-degree 122centi-degree Heavy metals (Pb):no more than 1.0mg/kg As:no more than 0.3mg/kg Cont of bacteria:no more than 300cfu/g Coliform:no more than 30cfu/g Pathogens: Negative