Solvent: carbon tetrachloride.

Internal standard— USP Benzyl Benzoate RS.

Procedure— Remove the gauze or other covering from 1or more Inhalant ampuls containing a total of 300to 400µLof amyl nitrite.Weigh accurately the clean and dry intact glass ampul(s),and place the weighed specimen in a freezer for not less than 15minutes.Transfer the chilled specimen to a glass-stoppered,25-mLconical flask containing a solution of 4to 5mEq of Internal standard,accurately weighed,in 1to 2mLof carbon tetrachloride.Break the ampul(s)with a glass rod,and rinse any sample or glass fragments adhering to the glass rod with 1mLof carbon tetrachloride into the main assay solution.Insert the stopper in the flask immediately,mix,and proceed as directed for Absolute Method of Quantitationunder Nuclear Magnetic Resonance á761ñ,beginning with “When dissolution has been completed.”With no spinning,or with the spinning adjusted so that the spinning side bands of neither the substance under assay nor the Internal standardinterfere with the regions to be integrated,record as ASthe average area of the Internal standardsinglet appearing at about 5.3ppm,representing the methylene protons of benzyl benzoate,and record as AUthe average area of the multiplet with a band center at about 4.8ppm,representing the alpha methylene protons of amyl nitrite,with reference to the tetramethylsilane singlet at 0ppm.Calculate the quantity of C5H11NO2in the Inhalant taken,using 58.57as the equivalent weight of amyl nitrite (EWU)and 106.12as that of benzyl benzoate (EWS).Rinse the flask containing the assay preparation with three 5-mLportions of ether,decanting each rinsing carefully to avoid loss of glass fragments,and evaporate any remaining ether with the aid of a current of dry air.Transfer the dry glass fragments to a tared watch glass,weigh,and subtract the weight of the glass fragments from that of the intact ampul(s)to obtain the weight of the Inhalant taken.