Magnetic dispersive solid-phase extraction based on magnetic metal-organic framework nanocomposite for the simultaneous detection of aflatoxins in edible oils

An efficient adsorbent composed of magnetic Fe3O4 particles and Al-based metal-organic framework (BUT-18) was prepared for magnetic dispersive solid-phase extraction (MDSPE) of four aflatoxins including B1, B2, G1, and G2 at trace amount in edible vegetable oils prior to analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Many parameters during MDSPE procedure such as amount of solvent used for extraction, extraction time, adsorbent amount, pH values, and desorption solvent were evaluated. Under optimal conditions, good limits of detections (LODs) and quantifications (LOQs) were achieved in the ranges of 0.1–0.4 μg/kg and 0.4–1.2 μg/kg, respectively. The established method was validated in terms of linearity (2–100 μg/kg) with correlation coefficient (R2 > 0.996). The recoveries of four aflatoxins in three oils spiked at three different concentrations (5, 10 and 20 μg/kg) were 70.1–90.73%, and the coefficient of variation was less than 6.54%. The developed approach demonstrates enormous potential for the determination of aflatoxins in real edible vegetable oils.