» Undecylenic Acid contains not less than 97.0 percent and not more than 100.5 percent of C11H20O2.
Packaging and storage Preserve in tight, light-resistant containers.
A: To 1 mL add potassium permanganate TS, dropwise: the permanganate color is discharged.
B: Place 3 mL of it and 3 mL of freshly distilled aniline in a tall test tube, and heat for 10 minutes at a rate such that the ring of condensate remains just below the mouth of the tube. Cool, add 10 mL of alcohol and 10 mL of ether, and transfer to a separator. Wash the ether solution with four 20-mL portions of water, and discard the water washings. Heat on a steam bath until the odor of ether no longer is perceptible, then add a few mg of activated carbon, mix, and filter. Evaporate the filtrate nearly to dryness, and recrystallize the residue from 70 percent alcohol: the anilide so obtained melts between 66 and 67.5.
Specific gravity 841: between 0.910 and 0.913.
Congealing range 651: not lower than 21.
Refractive index 831: between 1.447 and 1.448.
Residue on ignition 281: not more than 0.15%.
Water-soluble acids Shake 5 mL with 5 mL of water, and filter the water layer through a filter paper previously moistened with water. Add 1 drop of methyl orange TS, and titrate with 0.01 N sodium hydroxide VS: not more than 1.0 mL of 0.010 N sodium hydroxide is required to match the color produced by 1 drop of methyl orange TS in 5 mL of water.
Heavy metals, Method II 231: 0.001%.
Iodine value 401: between 131 and 138.
Assay Dissolve about 750 mg of Undecylenic Acid, accurately weighed, in 50 mL of alcohol, add 3 drops of phenolphthalein TS, and titrate with 0.1 N sodium hydroxide VS to the first pink color that persists for not less than 30 seconds. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N sodium hydroxide is equivalent to 18.43 mg of C11H20O2.