Analysis of synthetic antioxidants and preservatives in edible vegetable oil by HPLC/TOF-MS

The application of high performance liquid chromatography time-of-flight mass spectrometry (HPLC/TOF-MS) for the qualitation and quantitation of 11 synthetic antioxidants and preservatives in edible vegetable oil samples is reported here. The qualitation by HPLC/TOF-MS is accomplished with the accurate mass of the deprotonated molecules [M−H]−, along with the accurate mass of their main fragment ion. In order to obtain sufficient sensitivity for quantitation purposes (using deprotonated molecule), segment programme of fragmentor voltage is designed in negative ion mode. The mass accuracy typically obtained is routinely better than 5 ppm. The 11 compounds behave linearly in the 0.05–5.0 mg/kg concentration range, with correlation coefficient >0.997. The recoveries at the tested concentrations of 0.1–2.0 mg/kg are 65.8–106.9%, with coefficients of variation <8.1%. The method illustrated is suitable for routine qualitative and quantitative analyses of synthetic antioxidants and preservatives in edible vegetable oils.