Objective To establish a method for detecting perfluorooctanesulfonate(PFOS) and perfluorooctanoic acid(PFOA) in three kinds of animal food.Methods Samples were extracted by methanol and cleaned-up by SPE in a WAX column.The analytes were separated and detected on ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) by C18 column with mobile phase of methanol and 2 mmol/L ammonium acetate aqueous solution,and performed with negative EST at multiple reaction monitoring(MRM...