Glacial Acetic Acid DEFINITION Glacial Acetic Acid contains NLT 99.5% and NMT 100.5%, by weight, of C2H4O2. IDENTIFICATION • Identification TestsGeneral, Acetate 191: Meets the requirements Sample solution (for lanthanum nitrate test): Glacial Acetic Acid and water (1:100) ASSAY • Procedure Sample solution: Measure 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. Analysis: Add 20 mL of water, then add phenolphthalein TS. Titrate with 1 N sodium hydroxide VS. Each mL of 1 N sodium hydroxide is equivalent to 60.05 mg of C2H4O2. Acceptance criteria: 99.5%100.5% IMPURITIES Inorganic Impurities • Limit of Nonvolatile Residue: Evaporate 20 mL in a tared dish, and dry at 105 for 1 h: the weight of the residue does not exceed 1.0 mg. • Heavy Metals 231: NMT 5 ppm Sample solution: 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. • Chloride and Sulfate, Chloride 221 Sample solution: Dilute 1.0 mL with 20 mL of water. Analysis: Add 5 drops of silver nitrate TS. Acceptance criteria: No opalescence is produced. • Chloride and Sulfate, Sulfate 221 Sample solution: Dilute 1.0 mL with 10 mL of water. Analysis: Add 1 mL of barium chloride TS. Acceptance criteria: No turbidity is produced. Organic Impurities • Procedure: Readily Oxidizable Substances Sample solution: Dilute 2.0 mL in a glass-stoppered vessel with 10 mL of water. Analysis: Add 0.10 mL of 0.10 N potassium permanganate. Acceptance criteria: The pink color is not changed to brown within 2 h. SPECIFIC TESTS • Congealing Temperature 651: NLT 15.6 ADDITIONAL REQUIREMENTS • Packaging and Storage: Preserve in tight containers, and store at room temperature. Auxiliary Information Please check for your question in the FAQs before contacting USP.
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