Glacial Acetic Acid
»Glacial Acetic Acid contains not less than 99.5percent and not more than 100.5percent,by weight,of C2H4O2.
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.
Auxiliary Information Staff Liaison:Daniel K.Bempong,Ph.D.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28NF23Page 43Pharmacopeial Forum:Volume No.27(3)Page 2501