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Adipic Acid
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C6H10O4 146.1

Hexanedioic acid.
1,4-Butanedicarboxylic acid [124-04-9].
» Adipic Acid contains not less than 99.0 percent and not more than 101.0 percent of C6H10O4, calculated on the dried basis.
Add the following:
Packaging and storage— Preserve in a tight container. No storage requirements specified.NF24
USP Reference standards 11 USP Adipic Acid RS.
Identification, Infrared Absorption 197K .
Melting range 741: between 151 and 154.
Loss on drying 731 Dry it at 105 to constant weight: it loses not more than 0.2% of its weight.
Residue on ignition 281: not more than 0.1%.
Limit of nitrates—
Standard stock solution— Dissolve about 815 mg of potassium nitrate in 500 mL of water, and mix.
Standard solution— Dilute 1 mL of the Standard stock solution with water to 10 mL, and mix. Dilute 1 mL of this solution with water to 50 mL to obtain a solution containing 2 ppm of nitrate.
Test solution— Transfer 5 g of Adipic Acid to a 50-mL volumetric flask. Dissolve in water, with heating, and dilute with water to volume. Allow to cool and crystallize, then pass through a sintered-glass filter. Wash the filter with water, and collect the filtrate and washings until a volume of 50 mL is obtained. [NOTE—This solution is to be used in the tests for Chloride, Sulfate, Iron, and Heavy metals.]
Procedure— To 1.0 mL of the Test solution and to 1.5 mL of the Standard solution, separately add 2 mL of concentrated ammonia, 0.5 mL of manganese sulfate solution (1 in 100), and 1 mL of sulfanilamide solution (1 in 100), and dilute with water to 20 mL. Add 100 mg of zinc powder, and cool in an ice bath for 30 minutes, shaking periodically. Filter 10 mL of the solution, cool in an ice bath, and then add 2.5 mL of hydrochloric acid and 1 mL of a naphthylethylenediamine dihydrochloride solution (1 in 100). Allow to stand at room temperature for 15 minutes: the color of the Test solution is not darker than a concomitantly prepared Standard solution; the limit is 0.003%. The test is invalid if a concomitantly prepared blank solution (prepared using 1 mL of water instead of 1 mL of the Test solution) is darker than a solution containing 2 mg of potassium permanganate per L.
Chloride 221 A 5-mL portion of the Test solution from the Limit of nitrates test shows no more chloride than a corresponding 0.14-mL portion of 0.020 N hydrochloric acid: the limit is 0.02%.
Sulfate 221 A 5-mL portion of the Test solution from the Limit of nitrates test shows no more sulfate than a corresponding 0.26-mL portion of 0.020 N sulfuric acid: the limit is 0.05%.
Iron 241 Use a 10-mL portion of the Test solution from the Limit of nitrates test: the limit is 0.001%.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay— Dissolve 60 mg of Adipic Acid in 50 mL of water. Add 0.2 mL of phenolphthalein TS, and titrate with 0.1 N sodium hydroxide VS to a permanent pale pink endpoint. Each mL of 0.1 N sodium hydroxide is equivalent to 7.31 mg of C6H10O4.
Auxiliary Information— Staff Liaison : Catherine Sheehan, B.Sc., Scientist
Expert Committee : (EM105) Excipient Monographs 1
USP29–NF24 Page 3267
Pharmacopeial Forum : Volume No. 31(1) Page 87
Phone Number : 1-301-816-8262