Ethyl Acetate
;)
Acetic acid,ethyl ester.
Ethyl acetate [141-78-6].
»Ethyl Acetate contains not less than 99.0percent and not more than 100.5percent of C4H8O2.
Packaging and storage—
Preserve in tight containers,and avoid exposure to excessive heat.
Identification—
It is readily volatilized even at low temperatures and is flammable;when burned,a yellow flame and an acetous odor are produced.
Specific gravity á841ñ:
between 0.894and 0.898.
Acidity—
Asolution of 2.0mLin 10mLof neutralized alcohol requires not more than 0.10mLof 0.10Nsodium hydroxide for neutralization,2drops of phenolphthalein TSbeing used as the indicator.
Readily carbonizable substances á271ñ—
Pour 2mLcarefully upon 10mLof sulfuric acid TSso as to form separate layers:no dark zone is developed within 15minutes.
Limit of nonvolatile residue—
Evaporate it in a tared porcelain dish on a steam bath,and dry at 105
for 1hour:not more than 0.02%of residue remains.
for 1hour:not more than 0.02%of residue remains.
Limit of methyl compounds—
Place 20mLin a 500-mLseparator,add a solution of 20g of sodium hydroxide in 50mLof water,insert the stopper in the separator,and wrap it securely in a towel for protection against the heat of the reaction.Shake the mixture vigorously for about 5minutes,cautiously opening the stopcock from time to time to permit the escape of air.Continue shaking vigorously until a homogeneous liquid results,then distill,and collect about 25mLof the distillate.To 0.05mLof the distillate add 1drop of dilute phosphoric acid (1in 20)and 1drop of potassium permanganate solution (1in 20).Mix,allow to stand for 1minute,and add sodium bisulfite 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 steam bath at 60for 10minutes:no violet color appears.
for 10minutes:no violet color appears.
Chromatographic purity—
Chromatographic system (see Chromatography á621ñ)—
The gas chromatograph is equipped with a flame-ionization detector and a 1.8-m ×4-mm column that contains support S11.The column temperature is maintained at 115for 6minutes,then programmed to rise at 16per minute to 200,and held at 200for 15minutes.Prepare a mixture of chloroform,ethyl acetate,isobutyl acetate,and n-butyl acetate (3:1:1:1),and inject 0.1µL,using a 1-µLsyringe,into the chromatograph.In the resulting chromatogram,the retention times,relative to ethyl acetate as 1.0,are about 0.9for chloroform,2.7for isobutyl acetate,and 2.8for n-butyl acetate;and the tailing factor,T,for the ethyl acetate peak is not more than 1.5;the resolution,R,between the chloroform and ethyl acetate peaks is not less than 1.3,and the resolution,R,between the isobutyl acetate and n-butyl acetate peaks is not less than 1.5.
for 6minutes,then programmed to rise at 16per minute to 200,and held at 200for 15minutes.Prepare a mixture of chloroform,ethyl acetate,isobutyl acetate,and n-butyl acetate (3:1:1:1),and inject 0.1µL,using a 1-µLsyringe,into the chromatograph.In the resulting chromatogram,the retention times,relative to ethyl acetate as 1.0,are about 0.9for chloroform,2.7for isobutyl acetate,and 2.8for n-butyl acetate;and the tailing factor,T,for the ethyl acetate peak is not more than 1.5;the resolution,R,between the chloroform and ethyl acetate peaks is not less than 1.3,and the resolution,R,between the isobutyl acetate and n-butyl acetate peaks is not less than 1.5.
Procedure—
Using a 1-µLsyringe,inject a suitable volume (about 0.06µL)of Ethyl Acetate into the chromatograph,record the chromatogram,and measure the areas of all the peaks.The area of the ethyl acetate peak is not less than 99.5%of the sum of the areas of all the peaks.
Organic volatile impurities,Method Iá467ñ:
meets the requirements,the following modifications to the Chromatographic Systembeing made.The gas chromatograph contains a 0.53-mm ×30-m fused-silica analytical column coated with a 1-µm G16stationary phase;the carrier gas has a linear velocity of about 10cm per second;and the makeup gas,nitrogen,has a flow rate of about 30mLper minute.The column temperature is programmed according to the following steps:it is maintained at 50for 12minutes,then increased to 175at a rate of 8per minute,followed by an increase to 230at a rate of 35per minute,and maintained for at least 16minutes.
for 12minutes,then increased to 175at a rate of 8per minute,followed by an increase to 230at a rate of 35per minute,and maintained for at least 16minutes.
Assay—
Transfer about 1.5g of Ethyl Acetate,accurately weighed in a tared,stoppered weighing bottle,to a suitable flask,add 50.0mLof 0.5Nsodium hydroxide VS,and heat on a steam bath under a reflux condenser for 1hour.Allow to cool,add phenolphthalein TS,and titrate the excess sodium hydroxide with 0.5Nhydrochloric acid VS.Perform a blank determination (see Residual Titrationsunder Titrimetry á541ñ).Each mLof 0.5Nsodium hydroxide is equivalent to 44.05mg of C4H8O2.
Auxiliary Information—
Staff Liaison:Catherine Sheehan,B.Sc.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3002
Pharmacopeial Forum:Volume No.27(4)Page 2797
Phone Number:1-301-816-8262