Abstract: A method for the determination of nine phenolic antioxidants in vegetable oil by pass-through solid phase extraction (SPE) cleanup combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established. The antioxidants in samples were extracted with 0.5% formic acid-acetonitrile (V/V), purified by a pass-through SPE procedure on an Oasis? PRiME HLB column. The chromatographic separation was carried out using a C18 column with gradient elution using a mobile phase consisting of acetonitrile and water. The target compounds were detected by triple quadrupole mass spectrometry with electrospray ionization (ESI) under the multiple reaction monitoring (MRM) mode. The calibration curves of the nine antioxidants showed good linearity in their own ranges with correlation coefficients of higher than 0.994. The average recoveries ranged from 82.2% to 115.2% at three spiking levels with relative standard deviation (RSD) of less than 9.3%. The limits of detection (LODs) of the analytes were in the range of 0.003-0.02 mg/kg. The limits of quantitation (LOQs) of the analytes were in the range of 0.01–0.05 mg/kg. This rapid and sensitive method is suitable for the detection of antioxidants in vegetable oil.

Key words: vegetable oil; antioxidants; pass-through solid phase extraction cleanup; ultra-high performance liquid chromatography-tandem mass spectrometry