Method for detecting impurity morpholine in pebiprofen

The invention discloses a method for detecting impurity morpholine in pebiprofen, which comprises the following steps: S1, taking a pebiprofen bulk drug, precisely weighing, adding a solvent for dissolving, adding an extraction solvent, and carrying out vortex, centrifugation and separation to obtain a water phase; wherein a preparation method of the extraction solution comprises the following steps: taking a proper amount of water, and adjusting the pH value to 2-7 by using a hydrochloric acid solution; s2, taking a proper amount of the water phase in the step S1, placing the water phase in a measuring flask, and diluting the water phase with a diluent to a constant volume to obtain a test solution; and S3, testing the test solution in the step S2 by adopting gas chromatography, recording a chromatogram and reading related data. Morpholine is extracted from a pebiprofen raw material by adopting an extraction method, so that no interference peak exists before and after a morpholine peak, the detection accurac