A joint experimental-computational investigation: Metal organic framework as a vortex assisted dispersive micro-solid-phase extraction sorbent coupled with UPLC-MS/MS for the simultaneous determination of amphenicols and their metabolite in aquaculture water

In this work, vortex assisted dispersive micro-solid-phase extraction based on novel porous metal organic framework (MOF) was proposed and applied for the simultaneous determination of amphenicols and the metabolite in aquaculture water with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detection. The experimental parameters were systematically optimized to obtain higher extraction efficiency, the optimal conditions were as follows: the amounts of MIL-101(Cr), 10 mg; pH of samples was 11; adsorption time, 30 min; desorption solvent, 600 mu L methanol; desorption time, 20 min; salt concentration, 0%. Under the optimal conditions, the limits of detection (LOD5) and quantification (LOQs) for the target compounds were in the ranges of 0.05-0.15 mu g/L and 0.17-0.49 mu g/L, respectively. A good linearity was achieved in the concentration range of 0.2-20 mu g/L for florfenicol and florfenicol amine and 0.5-50 mu g/L for chloramphenicol and thiamphenicol with the correlation coefficients (r) larger than 0.9951. The relative recoveries were in the range from 70.1 +/- 9.5% to 109.2 +/- 5.7%. In addition, computer-aided molecular simulation was applied to elucidate the molecular interactions and the free binding energies between MIL-101(Cr) and the analytes, offering a better understanding of adsorption mechanism. The proposed method presented the advantages of rapid, accurate, sensitive, low matrix effect and environmental friendly property and it would be helpful for the trace analysis of amphenicols and metabolite. (C) 2016 Elsevier B.V. All rights reserved.