Dispersive solid-phase extraction using the metal–organic framework MIL-101(Cr) for determination of benzo(a)pyrene in edible oil

Abstract

Dispersive solid phase extraction (d-SPE) is a preponderant methodology featuring direct contact and interaction between adsorbents and analytes. Herein, we used the porous metal–organic framework (MOF) MIL-101(Cr) as a d-SPE adsorbent for pretreatment of edible oil samples and determination of benzo[a]pyrene (BaP). The samples after treatment are applied to determination by high performance liquid chromatography coupled with a fluorescence detector (HPLC-FLD). We optimized the type and dosage of the MOF, diluent and eluent. Under the optimized conditions, this method gave a linear calibration curve for the determination of BaP in the range of 1–30 ng mL⁻¹ (R² = 0.9958) and the relative standard deviation (RSD) ranged from 1.07 to 8.14% (n = 6). The limit of detection was 0.19 ng mL⁻¹ (S/N = 3) and the recoveries from different types of spiked oil samples were between 88.8 and 118.8%. Compared with conventional methods, the MOF-based d-SPE reduces organic solvent consumption and simplifies operation, which provides potential for application in extraction of hydrophobic targets from oil complexes.