Undecylenic Acid
;)
10-Undecenoic acid.
10-Undecenoic acid [112-38-9].
»Undecylenic Acid contains not less than 97.0percent and not more than 100.5percent of C11H20O2.
Packaging and storage—
Preserve in tight,light-resistant containers.
Identification—
A:
To 1mLadd potassium permanganate TS,dropwise:the permanganate color is discharged.
B:
Place 3mLof it and 3mLof freshly distilled aniline in a tall test tube,and heat for 10minutes at a rate such that the ring of condensate remains just below the mouth of the tube.Cool,add 10mLof alcohol and 10mLof ether,and transfer to a separator.Wash the ether solution with four 20-mLportions 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 70percent alcohol:the anilide so obtained melts between 66
and 67.5.
and 67.5.
Specific gravity á841ñ:
between 0.910and 0.913.
Congealing range á651ñ:
not lower than 21.
.
Refractive index á831ñ:
between 1.447and 1.448.
Residue on ignition á281ñ:
not more than 0.15%.
Water-soluble acids—
Shake 5mLwith 5mLof water,and filter the water layer through a filter paper previously moistened with water.Add 1drop of methyl orange TS,and titrate with 0.01Nsodium hydroxide VS:not more than 1.0mLof 0.010Nsodium hydroxide is required to match the color produced by 1drop of methyl orange TSin 5mLof water.
Heavy metals,Method IIá231ñ:
0.001%.
Iodine value á401ñ:
between 131and 138.
Assay—
Dissolve about 750mg of Undecylenic Acid,accurately weighed,in 50mLof alcohol,add 3drops of phenolphthalein TS,and titrate with 0.1Nsodium hydroxide VSto the first pink color that persists for not less than 30seconds.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nsodium hydroxide is equivalent to 18.43mg of C11H20O2.
Auxiliary Information—
Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 2004
Phone Number:1-301-816-8394