Glacial Acetic Acid
» Glacial Acetic Acid contains not less than 99.5 percent and not more than 100.5 percent, by weight, of C2H4O2.
Packaging and storage Preserve in tight containers, and store at room temperature.
Identification A mixture of 1 volume of it with 2 volumes of water responds to the tests for Acetate 191.
Congealing temperature 651: not lower than 15.6.
Limit of nonvolatile residue Evaporate 20 mL in a tared dish, and dry at 105 for 1 hour: the weight of the residue does not exceed 1.0 mg.
Chloride Dilute 1.0 mL with 20 mL of water, and add 5 drops of silver nitrate TS: no opalescence is produced.
Sulfate Dilute 1.0 mL with 10 mL of water, and add 1 mL of barium chloride TS: no turbidity is produced.
Heavy metals 231 To the residue obtained in the test for Limit of nonvolatile residue add 8 mL of 0.1 N hydrochloric acid, warm gently until solution is complete, dilute with water to 100 mL, and use 20 mL of the solution: the limit is 5 ppm.
Readily oxidizable substances Dilute 2.0 mL in a glass-stoppered vessel with 10 mL of water, and add 0.10 mL of 0.10 N potassium permanganate: the pink color is not changed to brown within 2 hours.
Assay Measure about 2 mL of Glacial Acetic Acid into a glass-stoppered flask, previously tared while containing about 20 mL of water, and weigh again to obtain the weight of the substance under assay. Add 20 mL of water, then add phenolphthalein TS, and titrate with 1 N sodium hydroxide VS. Each mL of 1 N sodium hydroxide is equivalent to 60.05 mg of C2H4O2.
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USP32NF27 Page 1419Pharmacopeial Forum: Volume No. 27(3) Page 2501