Determination of perfluorooctanoic acid and perfluorooctane sulphonic acid in edible vegetable oils using QuEChERS and high performance liquid chromatography-tandem mass spectrometry

In this study, a rapid, effective method based on QuEChERS was optimised and validated for determination of perfluorooctanoic acid (PFOA) and perfluorooctane sulphonic acid (PFOS) in edible vegetable oils by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Samples were simply vortex extracted with methanol containing 1% ammonia solution and purified through C18, PSA and GCB, followed by determination with HPLC-MS/MS. The detection parameters, including the mobile phase composition, the chromatographic column, as well as the sample preparation conditions, such as the choice of extraction solvents and the dosage of C18, PSA and GCB cleanup agents were optimised. The quantification of target compounds was carried out using stable isotope internal standards to compensate for any matrix effect during the electrospray ionisation process in the mass spectrometry. The developed method has demonstrated commendable accuracy, with recovery percentages ranging from 93.76% to 108.96%, and exhibits excellent precision, as indicated by relative standard deviation not exceeding 20%. Furthermore, the method has been validated for its selectivity, linearity of response, and sensitivity. The proposed method is beneficial for gathering residue data on PFOA and PFOS, allowing for the evaluation of their contamination levels in edible vegetable oils available in the Chinese market and providing scientific backing for regulatory supervision.