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 197M.

B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation obtained as directed in the Assay.

C: Prepare a solution of it in methanol containing 6 mg in each 5 mL. Proceed as directed under Thin-layer Chromatographic Identification Test 201, applying 5 µL of this solution and 5 µL of a similar solution of USP Trimeprazine Tartrate RS, using as the solvent system a mixture of 0.15 mL of ammonium hydroxide and 100 mL of acetone. Locate the spots on the plate by lightly spraying with iodoplatinic acid solution [prepared by dissolving 100 mg of chloroplatinic acid in 1 mL of 1 N hydrochloric acid, adding 25 mL of potassium iodide solution (1 in 25), diluting with water to 100 mL, and adding 0.5 mL of formic acid]: the RF value 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 0.005 M sodium 1-heptanesulfonate in methanol, water, and acetic acid (65:34:1). Make adjustments if necessary (see System Suitability under Chromatography 621).

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

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

Chromatographic system (see Chromatography 621)—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 1.5 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the capacity factor, k¢, is not less than 2.0 and not more than 5.0, the column efficiency is not less than 1200 theoretical 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 25 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of (C18H22N2S)2·C4H6O6 in the portion of Trimeprazine Tartrate taken by the formula: in which C is the concentration, in mg per mL, of USP Trimeprazine Tartrate RS in the Standard preparation, and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.