C12H14O4 222.24

1,2-Benzenedicarboxylic acid,diethyl ester.
Diethyl phthalate [84-66-2].

Packaging and storage— Preserve in tight containers.

USP Reference standards á11ñ— USP Diethyl Phthalate RS.

Identification,Infrared Absorption á197Fñ,on undried specimen.

Specific gravity á841ñ: between 1.118and 1.122,at 20.

Refractive index á831ñ: between 1.500and 1.505,at 20.

Acidity— Mix 20.0g with 50mLof alcohol that previously has been neutralized to a phenolphthalein endpoint,and titrate with 0.10Nsodium hydroxide to a phenolphthalein endpoint:not more than 0.50mLis required for neutralization.

Water,Method Iá921ñ: not more than 0.2%.

Residue on ignition á281ñ— Heat gently about 10g,accurately weighed,until the liquid has evaporated,and ignite the residue to constant weight.Not more than 0.02%is found.

Assay— Transfer about 1.5g of Diethyl Phthalate,accurately weighed,to a flask,add 50.0mLof 0.5Nalcoholic potassium hydroxide VS,attach a reflux condenser to the flask,and boil on a water bath for 1hour.Add 20mLof water,then add phenolphthalein TS,and titrate the excess potassium hydroxide with 0.5Nhydrochloric acid VS.Perform a blank determination (see Residual Titrations underTitrimetry á541ñ).Each mLof 0.5Npotassium hydroxide is equivalent to 55.56mg of C12H14O4.

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 2999

Phone Number:1-301-816-8262