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.
USP35NF30 Page 2065
Pharmacopeial Forum: Volume No. 36(3) Page 645
|