MIL-101@MF Composite Material Pipette-tip Efficient Solid-phase Extraction of Chloramphenicols Residues in Eggs
In this work,MIL-101@MF composites were created by employing polyvinylidene fluo-ride(PVDF)as a cross-linking agent to fix the metal-organic framework(MOF)Fe-MIL-101 on melamine foam(MF).Using the MIL-101@MF composites as adsorbents in the pipette-tip,a high performance MIL-101@MF with pipette-tip solid-phase extraction(PT-SPE)method was established.The antibiotic residues of chloramphenicol(CAP),thiamphenicol(TAP)and florfenicol(FF)in eggs were determined using this PT-SPE method combined with liquid chromatography tandem mass spec-trometry(LC-MS/MS).The morphology,crystal structure and functional groups of MIL-101@MF composites were characterized using scanning electron microscopy(SEM),powder X-ray diffraction analysis(XRD)and fourier transform-infrared spectroscopy(FTIR).These methods showed that the MOF Fe-MIL-101 was successfully synthesized and well immobilized on melamine foam.PT-SPE parameters were optimized,including pH,salt concentration,elution solvents,elution volume,the number of extraction and elution cycles.Samples were extracted and cleaned up after PT-SPE,the target compounds were analyzed by a Waters C18(100 mm×2.1 mm,1.7 µm)column with 0.1％formic acid water(containing 5 mmol/L ammonium acetate)-acetonitrile as the mobile phase.The de-tection was carried out in the negative ion mode using multi-reaction monitoring(MRM).The matrix standard curve combined with internal standard method was selected for the quantitative determina-tion of chloramphenicols(CAP,TAP,FF).The results showed that due to the co-existence of inter-actions such as electrostatic force,π-π action,and hydrogen bonding,the MIL-101@MF compos-ites had a very high adsorption capacity for chloramphenicols.The extraction process could be fin-ished quickly in less than 3 minutes.Moreover,even after 60 reuses,the material held its stability.Under the optimal conditions,the three targets showed good linearity in the mass concentration range of0.1-10 µg/kg(r2＞0.999),and the limits of quantification(LOQs)were 0.1 µg/kg.The recover-ies ranged from 78.2％to 108％with the relative standard deviations(RSDs)not more than 8.5％.The method was applied to determine 80 batches of egg samples,2.50％of TAP was detected between 0.21 and 1.2 µg/kg,while 8.75％of FF was detected between 0.47 and 4.2 μg/kg.Compared with other methods,the developed MIL-101@MF pipette-tip solid-phase extraction method is easy to op-erate,sensitive and accurate in quantification.It is expected to be applied in the pretreatment of multi-veterinary drug residues in animal foods.It can provide technical support for residue monitoring for safety of China's imported and exported food.
metal-organic frameworksmelamine foampipette-tip solid-phase extractionliquid chromatography-tandem mass spectrometryeggchloramphenicols
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维普
