Functionalized ionic liquids-supported metal organic frameworks for dispersive solid phase extraction of sulfonamide...

Sulfonamides antibiotic residues are commonly found in environmental samples, which is highly concerning for public safety and environmental protection. The detection of sulfonamides antibiotics (SAs) is quite important but challenging. In this work, functionalized Zr metal-organic frameworks (Zr-MOFs) and imidazole-based ionic liquids (ILs) were selected and designed according to the structures and properties of SAs. By supporting functionalized ILs into the water-stable Zr-MOFs, the novel ILs@Zr-MOFs nanocomposites were synthesized for the pretreatment of SAs. [H₂Nmim][NTf₂]@UiO-66-Br showed good selectivity for SAs with maximum adsorption capacity of 352.1 mg g^-1 for sulfadiazine. The satisfied performance attributed to not only the large BET surface areas, but also the multiple interactions between the adsorbent and SAs, including electrostatic interaction, hydrogen bonding interaction and π-π interaction. The as-prepared nanocomposites were applied to the dispersive solid phase extraction of SAs in environmental water samples. Combined with high performance liquid chromatography-diode array detector (HPLC-DAD), the effective extraction and sensitive analysis of SAs was achieved by [H₂Nmim][NTf₂]@UiO-66-Br with enrichment factors higher than 270 and extraction recoveries between 90.5% and 101.9% in short extraction time (10 min). The detection limits were lower than 0.03 μg L^-1.