C7H6O 106.12

Benzaldehyde.
Benzaldehyde [100-52-7].

Packaging and storage— Preserve in well-filled,tight,light-resistant containers.

Specific gravity á841ñ: between 1.041and 1.046at 25.

Refractive index á831ñ: between 1.544and 1.546at 20.

Limit of hydrocyanic acid— Shake 0.5mLof it with 5mLof water,add 0.5mLof 1Nsodium hydroxide and 0.1mLof ferrous sulfate TS,and warm the mixture gently.Upon the addition of a slight excess of hydrochloric acid,no greenish blue color or blue precipitate is produced within 15minutes.

Limit of nitrobenzene— Dissolve 1mLof it in 20mLof alcohol,and mix with 10mLof water.Add 1-g portions of zinc and 1-mLportions of 2Nsulfuric acid,as needed,to maintain a brisk evolution of hydrogen for 1hour.Filter,evaporate the liquid to about 20mL,and boil 10mLof the concentrated liquid with 1drop of potassium dichromate TS:no purplish color is produced.

Chlorinated compounds— Wind a strip of 20-mesh copper gauze 1.5cm wide and 5cm long around the end of a copper wire.Heat the gauze in the nonluminous flame of a Bunsen burner until it glows without coloring the flame green.Permit the gauze to cool,and heat several times until a thick coat of oxide has formed.With a medicine dropper,apply 2drops of Benzaldehyde to the cooled gauze,ignite,and permit it to burn freely in the air.Again cool the gauze,add 2more drops of it,and burn as before.Repeat this process until a total of 6drops has been added and ignited.Then hold the gauze in the outer edge of the Bunsen flame,adjusted to a height of about 4cm:not even a transient green color is imparted to the flame.

Organic volatile impurities,Method Vá467ñ: meets the requirements.

Assay— Transfer about 1mLof Benzaldehyde to a tared,glass-stoppered weighing bottle,and weigh accurately.Loosen the stopper,and transfer the weighing bottle and contents to a 250-mLconical flask containing 25mLof a reagent prepared by dissolving 34.7g of hydroxylamine hydrochloride in 160mLof water and diluting this solution with alcohol to 1000mL.Rinse down the sides of the flask with 50mLof the reagent.Allow to stand for 10minutes,add 1mLof bromophenol blue TS,and titrate the liberated hydrochloric acid with 1Nsodium hydroxide VSto a light-green endpoint.Perform a blank determination (see Residual Titrationsunder Titrimetry á541ñ).Each mLof 1Nsodium hydroxide is equivalent to 106.1mg of C7H6O.

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 2963

Phone Number:1-301-816-8262