Alcohol
;)
Ethanol.
Ethyl alcohol [64-17-5].
»Alcohol contains not less than 92.3percent and not more than 93.8percent,by weight,corresponding to not less than 94.9percent and not more than 96.0percent,by volume,at 15.56
,of C2H5OH.
,of C2H5OH.
Packaging and storage—
Preserve in tight containers,remote from fire.
Identification—
A:
Mix 5drops in a small beaker with 1mLof potassium permanganate solution (1in 100)and 5drops of 2Nsulfuric acid,and cover the beaker immediately with a filter paper moistened with a solution recently prepared by dissolving 0.1g of sodium nitroferricyanide and 0.25g of piperazine in 5mLof water:an intense blue color is produced on the filter paper,the color becoming paler after a few minutes.
B:
To 5mLof a solution (1in 10)add 1mLof 1.0Nsodium hydroxide,then slowly (over a period of 3minutes)add 2mLof 0.1Niodine:the odor of iodoform develops,and a yellow precipitate is formed within 30minutes.
Specific gravity á841ñ:
between 0.812and 0.816at 15.56,indicating between 92.3%and 93.8%,by weight,or between 94.9%and 96.0%,by volume,of C2H5OH.
,indicating between 92.3%and 93.8%,by weight,or between 94.9%and 96.0%,by volume,of C2H5OH.
Acidity—
To 50mL,in a glass-stoppered flask,add 50mLof recently boiled water.Add phenolphthalein TS,and titrate with 0.020Nsodium hydroxide to a pink color that persists for 30seconds:not more than 0.90mLof 0.020Nsodium hydroxide is required for neutralization.
Limit of nonvolatile residue—
Evaporate 40mLin a tared dish on a water bath,and dry at 105for 1hour:the weight of the residue does not exceed 1mg.
for 1hour:the weight of the residue does not exceed 1mg.
Water-insoluble substances—
Dilute it with an equal volume of water:the mixture is clear and remains clear for 30minutes after cooling to 10.
.
Aldehydes and other foreign organic substances—
Place 20mLin a glass-stoppered cylinder that has been thoroughly cleaned with hydrochloric acid,then rinsed with water and finally with the Alcohol to be tested.Cool the contents to approximately 15,and add,by means of a carefully cleaned pipet,0.10mLof 0.10Npotassium permanganate,noting accurately the time of addition.Mix at once by inverting the stoppered cylinder,and allow it to stand at 15for 5minutes:the pink color does not entirely disappear.
,and add,by means of a carefully cleaned pipet,0.10mLof 0.10Npotassium permanganate,noting accurately the time of addition.Mix at once by inverting the stoppered cylinder,and allow it to stand at 15for 5minutes:the pink color does not entirely disappear.
Amyl alcohol and nonvolatile,carbonizable substances—
Allow 25mLto evaporate spontaneously from a porcelain dish,carefully protected from dust,until the surface of the dish is barely moist:no red or brown color is produced immediately upon the addition of a few drops of sulfuric acid.
Limit of acetone and isopropyl alcohol—
To 1.0mLadd 1.0mLof water,1.0mLof a saturated solution of dibasic sodium phosphate,and 3.0mLof a saturated solution of potassium permanganate.Warm the mixture to 45to 50,and allow to stand until the permanganate color is discharged.Add 3.0mLof 2.5Nsodium hydroxide,and pass,without washing,through a sintered-glass filter.Prepare a control by mixing 1.0mLof the saturated solution of dibasic sodium phosphate,3.0mLof 2.5Nsodium hydroxide,80µg of acetone,and 5.0mLof water.To each solution add 1mLof furfural solution (1in 100),allow to stand for 10minutes,then to 1.0mLof each solution add 3mLof hydrochloric acid:any pink color produced in the test solution is not more intense than that in the control.
to 50,and allow to stand until the permanganate color is discharged.Add 3.0mLof 2.5Nsodium hydroxide,and pass,without washing,through a sintered-glass filter.Prepare a control by mixing 1.0mLof the saturated solution of dibasic sodium phosphate,3.0mLof 2.5Nsodium hydroxide,80µg of acetone,and 5.0mLof water.To each solution add 1mLof furfural solution (1in 100),allow to stand for 10minutes,then to 1.0mLof each solution add 3mLof hydrochloric acid:any pink color produced in the test solution is not more intense than that in the control.
Methanol—
To 1drop add 1drop of water,1drop of dilute phosphoric acid (1in 20),and 1drop of potassium permanganate solution (1in 20).Mix,allow to stand for 1minute,and add sodium metabisulfite solution (1in 20),dropwise,until the permanganate color is discharged.If a brown color remains,add 1drop of the dilute phosphoric acid.To the colorless solution add 5mLof freshly prepared chromotropic acid TS,and heat on a water bath at 60for 10minutes:any violet color should not exceed that produced by 0.04mg of methanol in 1mLof water,treated in the same way as the sample.
for 10minutes:any violet color should not exceed that produced by 0.04mg of methanol in 1mLof water,treated in the same way as the sample.
Auxiliary Information—
Staff Liaison:Justin Lane,B.S.,Scientific Associate
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 61
Pharmacopeial Forum:Volume No.30(5)Page 1843
Phone Number:1-301-816-8323