C2H4O2 60.05

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

Packaging and storage— Preserve in tight containers,and store at room temperature.

Identification— Amixture of 1volume of it with 2volumes of water responds to the tests for Acetate á191ñ.

Congealing temperature á651ñ: not lower than 15.6.

Limit of nonvolatile residue— Evaporate 20mLin a tared dish,and dry at 105for 1hour:the weight of the residue does not exceed 1.0mg.

Chloride— Dilute 1.0mLwith 20mLof water,and add 5drops of silver nitrate TS:no opalescence is produced.

Sulfate— Dilute 1.0mLwith 10mLof water,and add 1mLof barium chloride TS:no turbidity is produced.

Heavy metals á231ñ— To the residue obtained in the test for Limit of nonvolatile residueadd 8mLof 0.1Nhydrochloric acid,warm gently until solution is complete,dilute with water to 100mL,and use 20mLof the solution:the limit is 5ppm.

Readily oxidizable substances— Dilute 2.0mLin a glass-stoppered vessel with 10mLof water,and add 0.10mLof 0.10Npotassium permanganate:the pink color is not changed to brown within 2hours.

Assay— Measure about 2mLof Glacial Acetic Acid into a glass-stoppered flask,previously tared while containing about 20mLof water,and weigh again to obtain the weight of the substance under assay.Add 20mLof water,then add phenolphthalein TS,and titrate with 1Nsodium hydroxide VS.Each mLof 1Nsodium hydroxide is equivalent to 60.05mg of C2H4O2.

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 43

Phone Number:1-301-816-8143