HPLC method for measuring related substances in Favipiravir

The invention discloses an HPLC method for measuring related substances in Favipiravir. According to the HPLC method for measuring related substances in Favipiravir, disclosed by the invention, specifically, a diode array detector is adopted, and acetonitrile (mobile phase A)-phosphate solution (mobile phase B) serves as a mobile phase. The method comprises the following steps: taking a proper amount of Favipiravir and related preparations containing Favipiravir, adding the substances into the mobile phase for preparing a solution of which every 1ml contains 0.2mg of Favipiravir, and taking the solution as a test solution; diluting into a solution of which every 1ml contains about 0.2mu g of Favipiravir by using the mobile phase, and taking the solution as a contrast solution; respectively performing sample introduction, wherein the sum of each impurity peak area in the chromatogram of the test solution is not more than the main peak area of the contrast solution. According to the method for detecting the related substances in Favipiravir and related preparations containing Favipiravir, disclosed by the invention, the conditions of the impurities and degradation products of Favipiravir can be rapidly and accurately detected. The operation is simple and convenient, the sensitivity is high, and the product quality can be well controlled.