Method for separating and determining LCZ696 and impurity thereof

The invention discloses a method for separating and determining LCZ696 and impurities thereof. The method comprises the following steps: 1) taking LCZ696 or a preparation containing the LCZ696, addingdiluent to dissolve to obtain a sample solution in the concentration of 0.1-10mg/ml; 2) taking the sample solution obtained in the step 1), adding the diluent to dilute for 50-1000 times to obtain acontrast solution; 3) adopting a chromatographic column taking octadecyl silane bonded silica gel as filler, setting the flow velocity of a moving phase as 0.8-1.2ml/min, wherein the moving phase is composed of moving phase A and moving phase B, the moving phase A is a buffer solution in concentration of 0.0001 to 1.0mol/L, 0.0001-10 part by volume of triethylamine is added in 100 parts by volumeof buffer solution, the moving phase is acetonitrile-methanol mixed solution, the volume ratio of the acetonitrile-methanol is 55-45: 45-55, and the moving phase enters the chromatographic column by adopting a gradient elution