High-Affinity Extraction and Accurate Determination of Mefentrifluconazole Residues in Fruits and Vegetables Based on Poly(Deep Eutectic Solvents) Vinyl-Functionalized Graphene Oxide Nanocomposite

In this work, an efficient and accurate method integrates a high-affinity poly(deep eutectic solvents) vinyl-functionalized graphene oxide nanocomposite (PDESs-VGO), miniaturized centrifugal-accelerated pipette tip extraction (CAPTE), and high-performance liquid chromatography-ultraviolet (HPLC-UV) detector for accurate determination of mefentrifluconazole (MFFCZ). PDESs-VGO is synthesized in an aqueous system under room temperature, employing deep eutectic solvents as modifiers, which enhance its water compatibility and recognition capability for MFFCZ. The high-affinity adsorbent exhibits synergistic adsorption interactions, including hydrogen bonding, π–π stacking, and electrostatic adsorption, alongside a high adsorption capacity of 162.0 mg/g and rapid mass transfer. The method achieves a low detection limit (0.3 ng/g), excellent linearity (0.001–2.0 μg/g, r = 0.9999), and high precision (relative standard deviation ≤ 7.2%) and accuracy (83.6%–118.2%). Validation and analysis of real samples indicate that this method is highly effective for monitoring MFFCZ in fruits and vegetables, thereby ensuring food safety and protecting human health. This work demonstrates that this functional graphene oxide nanocomposite has great potential as an adsorbent in analytical chemistry.