Detection method of organic impurity in pimavanserin

The invention provides detection method of organic impurity in pimavanserin. The method includes the steps of: conducting HPLC detection on pimavanserin, wherein the mobile phase in the HPLC detection process includes an aqueous phase and an organic phase, the aqueous phase is aqueous solution of acid, the organic phase is organic solution of acid; the acids in the aqueous phase and organic phase include formic acid, trifluoroacetic acid, or phosphoric acid; solvents in the organic solution include methanol or acetonitrile; and the organic impurities are compounds as shown in formula I. The detection method of organic impurity in pimavanserin uses a mobile phase formed by the aqueous phase and organic phase of specific substances for high performance liquid chromatography detection process on pimavanserin; the mobile phase can better separate the organic impurities, so that the method provided by the invention can accurately detect the organic impurities in pimavanserin. In addition, the detection method of organic impurity in pimavanserin has good stability, reproducibility and strong specificity.