NOTE—Throughout the following procedures,protect test or assay specimens,the Reference Standard,and solutions containing them,by conducting the procedures without delay,under subdued light,or using low-actinic glassware.

A: The retention time of the major peak in the chromatogram of the Assay preparationcorresponds to that in the chromatogram of the Standard preparationobtained as directed in the Assay.

B: Mix 10mLof Syrup with about 30mLof water in a separator,render the solution alkaline with 1Nsodium hydroxide,and extract with two 30-mLportions of ether.Transfer the ether extracts to a beaker,evaporate the ether by warming,and dissolve the residue in 5mLof methanol:5µLof this solution meets the requirements of Identificationtest Cunder Trimeprazine Tartrate.

Mobile phase andChromatographic system— Proceed as directed under the Assay.

Standard solution— Transfer about 60.6mg of USP Trimeprazine Tartrate RS,accurately weighed,to a 50-mLvolumetric flask.Add 5mLof dilute hydrochloric acid (1in 100)followed by 2mLof 30percent hydrogen peroxide,and heat at 60for 10minutes.Cool,dilute with 1Msodium bisulfite to volume,and mix.Transfer 10.0mLto a 60-mLseparator,add 2mLof sodium hydroxide solution (1in 2),and mix.Extract with three 30-mLportions of ether.Filter the extracts through ether-wetted anhydrous sodium sulfate into a 250-mLconical flask.Cautiously evaporate the flask to dryness.Dissolve the residue in 10.0mLof methanol,and filter if necessary.Each mLof this solution contains about 1mg of trimeprazine sulfoxide.Transfer 1.0mLof this solution to a 500-mLvolumetric flask,dilute with Mobile phaseto volume,and mix to obtain a solution containing about 0.0024mg per mLof trimeprazine sulfoxide,expressed as trimeprazine tartrate.

Test solution— Use the Assay preparationas directed under the Assay.

Procedure— Separately inject equal volumes (about 25µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the responses for the peaks.The Test solutionmay exhibit a minor peak whose retention time corresponds to the peak exhibited by the Standard solutionand whose retention time is about 0.6relative to the main peak.Calculate the concentration,in mg per mL,of trimeprazine sulfoxide,in the portion of Syrup taken by the formula: in which Cis the concentration,in mg per mL,of trimeprazine tartrate in the Standard solution;Vis the volume,in mL,of Syrup taken;596.89and 746.98are the molecular weights of trimeprazine and trimeprazine tartrate,respectively;and rUand rSare the peak responses obtained from the Test solutionand the Standard solution,respectively.Not more than 0.036mg per mLis found.

Mobile phase,Standard preparation,and Chromatographic system —Proceed as directed in the Assayunder Trimeprazine Tartrate.

Assay preparation— Using a “to contain”pipet,transfer an accurately measured volume of Syrup,equivalent to about 2.5mg of trimeprazine,to a 100-mLvolumetric flask containing 50mLof Mobile phase.Rinse the pipet with Mobile phase,collecting the rinses in the volumetric flask.Dilute with Mobile phaseto volume,and mix.

Procedure— Separately inject equal volumes (about 25µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C18H22N2Sin each mLof Syrup taken by the formula: in which Cis the concentration,in mg per mL,of USP Trimeprazine Tartrate RSin the Standard preparation;Vis the volume,in mL,of Syrup taken;596.89and 746.98are the molecular weights of trimeprazine and trimeprazine tartrate,respectively;and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.