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: Infrared Absorption á197Mñ.

B: 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.

C: Prepare a solution of it in methanol containing 6mg in each 5mL.Proceed as directed under Thin-layer Chromatographic Identification Test á201ñ,applying 5µLof this solution and 5µLof a similar solution of USP Trimeprazine Tartrate RS,using as the solvent system a mixture of 0.15mLof ammonium hydroxide and 100mLof acetone.Locate the spots on the plate by lightly spraying with iodoplatinic acid solution [prepared by dissolving 100mg of chloroplatinic acid in 1mLof 1Nhydrochloric acid,adding 25mLof potassium iodide solution (1in 25),diluting with water to 100mL,and adding 0.5mLof formic acid]:the RFvalue of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.

Test solution: methanol.

Standard solution: methanol.

Eluant: a mixture of ethyl acetate saturated with ammonium hydroxide and ether (1:1).

Visualization: 1.

Mobile phase— Prepare a filtered and degassed mixture of 0.005Msodium 1-heptanesulfonate in methanol,water,and acetic acid (65:34:1).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).

Standard preparation— Dissolve an accurately weighed quantity of USP Trimeprazine Tartrate RSin Mobile phase,and dilute quantitatively,and stepwise if necessary,with Mobile phaseto obtain a solution having a known concentration of about 0.031mg per mL.

Assay preparation— Transfer about 62mg of Trimeprazine Tartrate,accurately weighed,to a 100-mLvolumetric flask,dissolve in and dilute with Mobile phaseto volume.Transfer 5mLof this solution into a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.

Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm ×30-cm column that contains packing L1.The flow rate is about 1.5mLper minute.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the capacity factor,k¢,is not less than 2.0and not more than 5.0,the column efficiency is not less than 1200theoretical plates,the tailing factor is not more than 3.5,and the relative standard deviation for replicate injections is not more than 0.6%.

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 (C18H22N2S)2·C4H6O6in the portion of Trimeprazine Tartrate taken by the formula: in which Cis the concentration,in mg per mL,of USP Trimeprazine Tartrate RSin the Standard preparation,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.