This standard specifies a method for the determination of UV absorber content in cellulose triacetate ester (TAC) membranes by high performance liquid chromatograph. It is suitable for the determination of UV absorber content in TAC membranes. The sample is first dissolved with dichloromethane, and the polymer is settled by adding n-hexane, and then filtered through the filtrate membrane. Then use the High Performance Liquid Chromatograph to determine in accordance with the provisions of GB/T 16631 under appropriate conditions, and finally use the external standard method for quantification. The required reagents include dichloromethane, n-hexane, Chloroform, methanol, and methanol acetate solution. The purity of the UV absorber standard should not be less than 99.0%, and the standard stock solution of UV absorber should be prepared.