China (Mainland) 
cas no. : 1314-13-2
einecs: 215-222-5
molecular formula : zno
molecular weight : 81.38
properties : white powder,stable under normal temperature, good hiding power and colouring power.insoluble in water and alcohol ,soluble in acid ,alkali and amkonium solution.
use : zinc oxide pharmaceutical grade usp34 is mainly used for bandage,medicine,cosmetic,plaster,adhesive plaster,dental impression pastezinc ointment and etc
storage : store at a cool and dry place.
packing : 25kg woven bags lined with plastic bag(special packing can be made according to clients' requirement).
specification: zinc oxide pharmaceutical grade usp34( %
|
idex item |
standard |
|
assay(zno) |
99.0%-100.5% |
|
identification |
a:when stongly heated,it assumes a yellow color |
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|
that disappears on cooling |
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|
b:asolution of it in a slight excess of 3n |
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|
hydrochloric acid responds to the tests for |
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|
zinc<191> |
|
alkalinity |
mix 1.0g with 10ml of hot water,add 2 drops of |
|
|
phenolphthalein ts,and filter;if a red color |
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is produced.not more than 0.30ml of 0.10 n |
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hydrochloric acid is required to discharge it |
|
loss on ignition |
not more than 1.0% |
|
as |
not more than 6ppm |
|
carbonate and color of solution |
mix 2.0g with 10ml of water,add 30ml of 2n |
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sulfuric acid,and heat on a steam bath,with |
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contant stirring;no effervescence occours |
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|
and the resulting solution is clear and colorless |
|
lead(pb) |
add 2g to 20ml of water ,stir well ,add 5 ml of glacial acetic acid, and warm on a steam bath until solution is effected,the addition of 5 drops of potassium chromate ts produces no turbidity or precipitate |
|
iron and other heavy metals |
cooled 5ml portions of the solution obtained in the test for carbonate and color of solution yield white precipitates with potassium ferrocyanide ts and with sodium sulfide ts |
|
assay |
??dissolve about 1.5 g of freshly ignited zinc oxide, accurately weighed, and 2.5 g of ammonium chloride in 50.0 ml of 1 n sulfuric acid vs with the aid of gentle heat, if necessary. when solution is complete, add methyl orange ts, and titrate the excess sulfuric acid with 1 n sodium hydroxide vs. each ml of 1 n sulfuric acid is equivalent to 40.69 mg of zno. |