Zinc Oxide USP33
Item Standard Result
1)Appearance A soft, white or faintly yellowish-white, amorphous powder confirm
2)Assay % m/m 99.0~100.5 99.82
3)Identification Positive reaction Positive reaction
4)Alkalinity Add 0.1ml of phenolphthalein solution to the
mixture solution,filtered,,add hydrochloric acid to confirm
change the red colour to the indicator.
5)Carbonates and substances <=0.006 0.002
insoluble in acids %
6)PbO(tested in Pb) % <=0.005 0.002
7)Heavy metal(tested in Zn) % None None
8)MnO(tested in Mn) % <=0.0001 0.0001
9)CuO(tested in Cu) % <=0.0002 0.0002
10)As % <=0.0005 0.0004
11)Cd % <=0.001 0.0006
12)Loss on ignition % m/m <=0.2 0.1
13）Water dissoluble% <=0.1 0.08
14)105℃ volatile substances <=0.3 0.2
