[Determination of seven non-selective cyclooxygenase inhibitors in milk powder by ultra-performance liquid chromatography-tandem mass spectrometry with dispersive solid phase extraction].

An ultra-performance liquid chromatography-tandem mass spectrometry with dispersive solid phase extraction (dSPE-UPLC-MS/MS) method was developed to determine seven non-selective cyclooxygenase inhibitors in milk powder. The samples were extracted with 0.01 mol/L pH 2.5 ascorbic acid-acetonitrile-ethyl acetate solution (2:5:5, v/v/v), and then purified with a mixture of anhydrous sodium sulfate, octadecyl carbon silica gel (C