Method for testing content of tris (nonylphenyl) phosphite

The invention provides a method for testing the content of tris (nonylphenyl) phosphite, which comprises the following steps: A, weighing a sample, adding an organic solvent into the sample, and carrying out ultrasonic extraction in an ultrasonic tank to obtain an extract; B, centrifuging the extracting solution, taking supernatant, blowing nitrogen to be nearly dry, adding methanol for redissolving, and enabling the volume of the methanol to be the same as that of the supernatant; C, filtering the methanol redissolved solution into a sample bottle by using an organic phase filter membrane; and D, testing by using a high performance liquid chromatography-diode array detector combination instrument. The high performance liquid chromatograph diode array detector has high selectivity and response value to tris (nonylphenyl) phosphite, can perform qualitative and quantitative detection, and has strong anti-interference capability. The method provided by the invention is simple and rapid, and can be used for accur