项目Item                              分析纯(AR)     化学纯(CP)
灼烧失重Ignition loss,%         20～28        20～28  
氯化物(Cl)Chloride,%             ≤ 0.005         0.005
硫酸盐(SO₄)Sulfate,%            ≤ 0.02           0.02
铁(Fe)Iron,%                         ≤ 0.005         0.005
重金属Heavy metals,%          ≤ 0.005          0.01
不挥发物Novolatile                 ≤ 0.2             0.4

99.9% metals basis:

外观Appearance                                     White Powder
纯度Purity                                              ≥99.9% Based on Trace Metals Impurities
hydration of Silica %                               <0.5% Residue
总痕量金属杂质total metallic impurities    ≤1000ppm by ICP Atomic emission