Acetic acid.
Acetic acid [64-19-7].

Packaging and storage— Preserve in tight containers.

Identification— It responds to the tests for Acetate á191ñ.

Nonvolatile residue— Evaporate 20mLin a tared porcelain dish on a steam bath,and dry at 105for 1hour:the weight of the residue does not exceed 1.0mg (0.005%).

Chloride— Add 5drops of silver nitrate TSto 10mLof a solution (1in 10):no opalescence is produced.

Sulfate— Add 5drops of barium chloride TSto 10mLof a solution (1in 10):no turbidity is produced.

Heavy metals á231ñ— To the residue obtained in the test for Nonvolatile residueadd 8mLof 0.1Nhydrochloric acid,warm gently until solution is complete,dilute with water to 100mL,and use 10mLof the solution:the limit is 0.001%.

Readily oxidizable substances— Dilute 4.0mLin a glass-stoppered vessel with 20mLof water,and add 0.30mLof 0.10Npotassium permanganate:the pink color is not changed to brown at once,and the liquid does not become entirely brown or free from a pink tint in less than 30seconds.

Organic volatile impurities,Method IVá467ñ: meets the requirements.

Assay— Place about 6mLof Acetic Acid in a tared,glass-stoppered flask,and weigh accurately.Add 40mLof water,then add phenolphthalein TS,and titrate with 1Nsodium hydroxide VS.Each mLof 1Nsodium hydroxide is equivalent to 60.05mg of C2H4O2.

Expert Committee:(PA6)Pharmaceutical Analysis 6

USP28–NF23Page 2948

Phone Number:1-301-816-8389