A: Infrared Absorption á197Mñ.

B: Ultraviolet Absorption á197Uñ—

Test solution— Prepare a solution of Triazolam in chloroform containing about 2mg per mL.

Chromatographic system(see Chromatography á621ñ)— The gas chromatograph is equipped with a flame-ionization detector,and contains a 3-mm ×120-cm glass column packed with 3%phase G6on support S1AB.The column and injection port are maintained at a temperature of about 240.The detector is maintained at a temperature of about 20to 50above column temperature.The carrier gas is helium.

Procedure— [NOTE—Allow about three times the elution time of the major component before making another injection.]Chromatograph about 4µLof theTest solution.Calculate the total percentage of impurities taken by the formula: in whichSis the sum of the areas of each of the minor component peaks detected,andAis the area of the major component peak.The total amount of impurities present is not more than 1.5%.

Mobile phase— Prepare a filtered and degassed mixture of acetonitrile,chloroform,butyl alcohol,water,and glacial acetic acid (850:80:50:20:0.5).Make adjustments if necessary (seeSystem SuitabilityunderChromatography á621ñ).

Internal standard solution— Dissolve an accurately weighed quantity of alprazolam in acetonitrile,and dilute with acetonitrile to obtain a solution having a known concentration of about 0.3mg per mL.

Standard stock solution— Dissolve an accurately weighed quantity of USP Triazolam RSinInternal standard solution,and dilute withInternal standard solution to obtain a solution having a known concentration of about 0.25mg per mL.

Assay stock solution— Transfer about 2.5mg of Triazolam,accurately weighed,to a 10-mLvolumetric flask,dissolve in and dilute withInternal standard solution to volume,and mix.

Standard preparation— Dilute an accurately measured portion of theStandard stock solution with acetonitrile to obtain a solution having a known concentration of USP Triazolam RSof about 0.025mg per mL.

Assay preparation— Transfer about 5mLof theAssay stock solution,accurately measured,to a 50-mLvolumetric flask,dilute with acetonitrile to volume,and mix.

Chromatographic system(see Chromatography á621ñ)— The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm ×30-cm column that contains packing L3.The flow rate is about 2.0mLper minute.Chromatograph theStandard preparation,and record the peak responses as directed underProcedure:the relative retention times are 1for triazolam and about 1.4for the internal standard,the resolution,R,between the internal standard and triazolam is not less than 2.0,and the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Separately inject equal volumes (about 20µL)of theStandard preparation and theAssay preparation into the chromatograph,record the chromatograms,and measure the area responses for the major peaks.Calculate the quantity,in mg,of C17H12Cl2N4in the portion of Triazolam taken by the formula: in whichCis the concentration,in mg per mL,of USP Triazolam RSin theStandard stock solution;Vis the volume of internal standard used to prepare theAssay stock solution;andRUandRSare the ratios of the internal standard peak area to the alprazolam peak area obtained from theAssay preparation and theStandard preparation,respectively.