MIL-101(Cr)@GO for dispersive micro-solid-phase extraction of pharmaceutical residue in chicken breast used in microwave-assisted coupling with HPLC-MS/MS detection

In this work, MIL-101(Cr)@GO (Graphite Oxide) was synthesized using a hydrothermal synthesis method and was applied as a dispersive micro-solid-phase extraction (D-μ-SPE) sorbent for the efficient concentration of four residual drugs (metronidazole, MNZ; tinidazole, TNZ; chloramphenicol, CAP; sulfamethoxazole, SMX). Meanwhile, the extraction process was optimized by combining it with microwave-assisted extraction. Factors affecting the D-μ-SPE efficiency, such as selection of sorbent materials, pH of the sample solution, salting-out effect, amount of used material, extraction time, desorption solvent and desorption time, were studied. Under the optimal extraction conditions, the linearity ranged from 10 to 1000 ng kg−1 and 1-100 ng kg−1 (r2 ≥ 0.9928) for the target analytes. The limits of detection were between 0.08 and 1.02 ng kg−1, and the limits of quantitation were between 0.26 and 3.40 ng kg−1. Additionally, the developed method also exhibited good precision (RSD ≤ 2.5%), repeatability (RSD ≤ 4.3%), high recoveries (88.9%-102.3%) and low matrix effects (78.2%-95.1%). The proposed method proved to be an efficient and reliable approach for the determination of the analytes. Finally, we successfully detected the four drugs in chicken breast.