Determination method of benzal malonate ultraviolet absorbent in PBAT (poly (butylene adipate-co-terephthalate)) product

The invention discloses a method for determining a benzal malonate ultraviolet absorbent in a PBAT (poly (butylene adipate-co-terephthalate)) product. The determination method comprises the following steps: (1) preparing a standard working solution and a to-be-detected sample solution, the to-be-detected sample solution is obtained by the following steps: adding a chloroform solution into a PBAT sample to completely dissolve the sample, then adding a precipitation solvent and an ionic salt solution, uniformly mixing, carrying out centrifugal treatment to obtain an insoluble substance and a supernatant, and treating the supernatant until the supernatant is dried to obtain a to-be-detected sample solution; redissolving with a methanol-water solution, dropwise adding a NaOH solution into the redissolved solution until no obvious precipitate is generated in the solution, performing centrifugal treatment, taking supernate, and fixing the volume with the methanol-water solution to obtain a to-be-detected sample sol