Xiaomin Zhu,Shenping Zhang,Lihuo Zhang,Honglai Liu,Jun Hu
In situ interfacial growth of nanoparticles induced by the Pickering emulsion is a novel and convenient method for preparing hybrids/composites with specific tasks. For the first time, magnetic PMMA@Fe3O4/Cu3(BTC)2 hollow microspheres were produced by one-pot Pickering emulsion using Fe3O4 nanoparticle (NP) stabilizer. The Fe3O4 Pickering emulsion provided a large oil/water interface area for the in situ growth of Cu3(BTC)2 nanocrystals and further interfacial polymerization of polymethyl methacrylate (PMMA). The hollow hybrid microspheres showed synergetic multi-functions, including the magnetic separation property caused by Fe3O4 NPs, the reverse thermal expansion by PMMA, and the adsorption enhanced permeation by porous Cu3(BTC)2 NPs. When it was used as the drug carrier for ibuprofen, the good loading capacity and the controllable release duration confirmed its good properties. Moreover, all the realized synergetic advantages further reveled the potential promising applications of the interfacial synthesis by Pickering emulsion method.
Li Yan-ni,Hu Yan-yun,Ding Lei,Zhou Dian-bing,Chen Wen-jun
Residues of tetracycline antibiotics (TCs) in environments may be harmful to human. Due to their high polarities, it is extremely challenging to efficiently enrich TCs with low concentrations in natural waters for analysis. In this work, a magnetic metal-organic framework Fe 3 O 4 @[Cu 3 (btc) 2 ] was synthesized and applied as a dispersive micro-solid phase extraction adsorbent for TCs enrichment. Effects of dispersive micro-solid phase extraction conditions including extraction time, solution pH, and elution solvent on the extraction efficiencies of TCs were investigated. Results show that TCs could be enriched efficiently by Fe 3 O 4 @[Cu 3 (btc) 2 ], and electrostatic interaction between TCs and Fe 3 O 4 @[Cu 3 (btc) 2 ] dominated this process. Combined with liquid chromatography-tandem mass spectrometry, four TCs residues (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) in natural waters were determined. The detection limits (LOD, S/N = 3) of the four antibiotics were 0.01–0.02 µg/L, and the limits of quantitation (LOQ, S/N = 10) were 0.04–0.07 µg/L. The recoveries obtained from river water and aquaculture water spiked with three TCs concentration levels ranged from 70.3% to 96.5% with relative standard deviations of 3.8%–12.8%. Results indicate that the magnetic metal-organic framework based dispersive micro-solid phase extraction is simple, rapid and high-loading for antibiotics enrichment from water, which further expand the practical application of metal-organic frameworks in sample pretreatment for environmental pollutant analysis.
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