Limit of hydrazine
Mobile phase
Prepare a filtered and degassed mixture of methanol and 1% monobasic ammonium phosphate solution (75:25). Make adjustments if necessary (see
System Suitability under
Chromatography 621).
Standard solution
Transfer an accurately weighed quantity of about 42.0 mg of hydrazine sulfate, equivalent to about 10 mg of hydrazine, to a 100-mL volumetric flask. Dissolve in water, sonicate for about 5 minutes, dilute with methanol to volume, and mix. Dilute an accurately measured volume of this solution quantitatively and stepwise with methanol to obtain a solution having a known concentration of 5.0 µg of hydrazine per mL. Transfer 5.0 mL of this solution to a 200-mL volumetric flask, add 50 mL of methanol and 0.7 mL of ammonium hydroxide, and shake to mix. Add 0.5 mL of salicylaldehyde, shake by mechanical means for about 5 minutes, dilute with methanol to volume, sonicate for about 2 minutes, and mix.
Test solution
Transfer about 25.8 mg of Phenelzine Sulfate, accurately weighed, to a 200-mL volumetric flask, dissolve in about 50 mL of methanol, and sonicate. Add 0.7 mL of ammonium hydroxide, shake to mix, add 0.5 mL of salicylaldehyde, shake by mechanical means for about 5 minutes, dilute with methanol to volume, sonicate for about 2 minutes, and mix.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 340-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L1. Chromatograph the
Standard solution, and record the peak areas as directed for
Procedure: the relative retention times for salicylaldehyde, phenelzine sulfate derivative, and hydrazine sulfate derivative are about 0.21, 0.47, and 1.0, respectively; the column efficiency determined from the analyte peak is not less than 4500 theoretical plates; the resolution,
R, between phenelzine and salazine (derivatized hydrazine) is not less than 1.25; and the relative standard deviation for replicate injections is not more than 7%.
Procedure
Separately inject equal volumes (about 50 µL) of the
Standard solution and the
Test solution into the chromatograph, record the chromatograms, and measure the peak areas for salazine (derivatized hydrazine). Calculate the percentage of hydrazine in the portion of Phenelzine Sulfate taken by the formula:
20(C/W)(rU / rS),
in which
C is the concentration, in µg per mL, of hydrazine base in the
Standard solution; W is the weight, in mg, of Phenelzine Sulfate taken to prepare the
Test solution; and
rU and
rS are the salazine peak areas obtained from the
Test solution and the
Standard solution, respectively: not more than 0.1% is found.
Ordinary impurities 466
Test solution:
a mixture of methanol and water (1:1).
Standard solution:
a mixture of methanol and water (1:1).
Eluant:
acetone. [NOTEPrewash the plate with Eluant, and dry.]
Visualization:
1.
Assay
Assay preparation
Transfer about 26 mg of Phenelzine Sulfate, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
Procedure
Separately inject equal volumes (about 20 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the quantity, in mg, of C
8H
12N
2·H
2SO
4 in the portion of Phenelzine Sulfate taken by the formula:
100C(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Phenelzine Sulfate RS in the
Standard preparation; and
r U and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.