The invention relates to the technical field of
drug impurity detection, in particular to a method for detecting the content of aminoguanidine in a
lamotrigine key intermediate. Respectively dissolving the
test sample and the reference substance in a detection
solvent to obtain a
test sample solution and a reference substance solution; respectively separating the
test solution and the reference solution by adopting a liquid
chromatography technology, detecting by adopting a
mass spectrometry
detector, and calculating the content of aminoguanidine by adopting an external standard method according to a
peak area; the liquid
chromatography conditions are as follows: a C8
chromatographic column is adopted, and the flow rate is 0.95-1.05 ml / min; the
column temperature is 30-40 DEG C; the mobile phase is A: 0.1%
formic acid aqueous solution; b:
acetonitrile;
gradient elution is carried out for 0.0 to 0.8 min, and 90 percent of A is obtained; when the time is 0.8-2.0 min, 90%-10% of A is added; in 2.0-4.0 min, 10% of A is taken; the
mass spectrometry conditions are as follows: in an ESI + positive
ion mode, the taper hole
voltage is 38V, the parent
ion m / z is 75.2, the quantitative
ion pair m / z is 75.2 / 58.4, the quantitative ion collision energy is 11V, the qualitative ion pair m / z is 75.2 / 43.5, and the qualitative ion collision energy is 36V. The methodology verifies that the method can be used for quantitatively detecting the content of aminoguanidine in the
lamotrigine key intermediate.