Acetic Acid
(a see' tik as' id).

Acetic acid;    
Acetic acid     [64-19-7].
DEFINITION
Acetic Acid is a solution containing NLT 36.0% and NMT 37.0%, by weight, of C2H4O2.
IDENTIFICATION
•  A. Identification Tests—General, Acetate 191: Meets the requirements
ASSAY
•  Procedure
Analysis:  Place 6 mL in a tared, glass-stoppered flask, and weigh. Add 40 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:  36.0%–37.0%
IMPURITIES
•  Nonvolatile Residue
Analysis:  Evaporate 20 mL in a tared porcelain dish on a steam bath, and dry at 105 for 1 h.
Acceptance criteria:  The weight of the residue does not exceed 1.0 mg (0.005%).
•  Chloride
Sample solution:  Acetic acid (1 in 10) in water
Analysis:  To 10 mL of the Sample solution add 5 drops of silver nitrate TS.
Acceptance criteria:  No opalescence is produced.
•  Sulfate
Sample solution:  Acetic acid (1 in 10) in water
Analysis:  To 10 mL of the Sample solution add 5 drops of barium chloride TS.
Acceptance criteria:  No turbidity is produced.
•  Heavy Metals 231
Sample solution:  To the residue obtained in the test for Nonvolatile Residue add 8 mL of 0.1 N hydrochloric acid, warm gently until completely dissolved, and dilute with water to 100 mL. Use 10 mL of this solution.
Acceptance criteria:  NMT 10 ppm
•  Readily Oxidizable Substances
Analysis:  Dilute 4.0 mL in a glass-stoppered vessel with 20 mL of water, and add 0.30 mL of 0.10 N potassium permanganate.
Acceptance criteria:  The pink color is not changed to brown at once, and the liquid does not become entirely brown or free from a pink tint in less than 30 s.
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in tight containers.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Feiwen Mao, M.S.
Senior Scientific Liaison
1-301-816-8320
(SM32010) Monographs - Small Molecules 3
USP35–NF30 Page 1681