Items 检测项目 Standard 检测标准 Appearance 外观 Off-White powder and particles 类白色粉末和颗粒 Assay 含量 Not less than 60% 不低于60% Iron(Fe) 铁 Not more than 10ppm 不超过 10ppm Loss on Drying 干燥失重 Not more than 10% 不超过 10% Residue on ignition (sulfated) 灼烧残渣 Not more than 0.50% 不超过 0.50% Heavy metal(Pb) 重金属（铅） Not more than 20ppm 不超过 20ppm （S） 硫 Not more than 0.05% 不超过0.05%