舍曲林的测定

Related substances
Gas chromatography (2.2.28): use the normalisation procedure.

Test solution Introduce 0.250 g of the substance to be examined into a 15 ml stoppered centrifuge tube, add 2.0 ml of methanol R and 0.20 ml of a 25 per cent solution of potassium carbonate R and mix in a vortex mixer for 30 s. Add 8.0 ml of methylene chloride R, stopper the tube and mix in a vortex mixer for 60 s. Add 1 g of anhydrous sodium sulphate R, mix well and then centrifuge for about 5 min.

Reference solution (a) Dissolve the contents of a vial of sertraline for peak identification CRS (containing impurities A, B, C and F) in 0.2 ml of methylene chloride R.

Reference solution (b) Dilute 1.0 ml of the test solution to 100.0 ml with methylene chloride R. Dilute 1.0 ml of this solution to 20.0 ml with methylene chloride R.

Column:
— material: fused silica;
— size: l = 30 m, Ø = 0.53 mm;
— stationary phase: polymethylphenylsiloxane R (film thickness 1.0 µm).
Carrier gas helium for chromatography R.

Flow rate 9 ml/min.

Split ratio 1:10.

Temperature:





Detection Flame ionisation.

Injection 1 µl.

Identification of impurities Use the chromatogram supplied with sertraline for peak identification CRS and the chromatogram obtained with reference solution (a) to identify the peaks due to impurities A, B, C and F.

Relative retention With reference to sertraline (retention time = about 24 min): impurity B = about 0.5; impurities C and D = about 0.7; impurity A = about 1.05; impurity F = about 1.1.

System suitability Reference solution (a):

— peak-to-valley ratio: minimum 15, where Hp = height above the baseline of the peak due to impurity A and Hv = height above the baseline of the lowest point of the curve separating this peak from the peak due to sertraline.
Limits:
— impurities A, B, F: for each impurity, maximum 0.2 per cent;
— sum of impurities C and D: maximum 0.8 per cent;
— unspecified impurities: for each impurity, maximum 0.10 per cent;
— total: maximum 1.5 per cent;
— disregard limit: the area of the principal peak in the chromatogram obtained with reference solution (b) (0.05 per cent).