Facile magnetization of metal-organic framework MIL-101 for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons in environmental water samples

Analyst. 2012 Aug 7;137(15):3445-51. doi: 10.1039/c2an35429b. Epub 2012 Jun 13.

Abstract

The unusual properties such as high surface area, good thermal stability, uniform structured nanoscale cavities and the availability of in-pore functionality and outer-surface modification make metal-organic frameworks (MOFs) attractive for diverse analytical applications. However, integration of MOFs with magnets for magnetic solid-phase extraction for analytical application has not been attempted so far. Here we show a facile magnetization of MOF MIL-101(Cr) for rapid magnetic solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. MIL-101 is attractive as a sorbent for solid-phase extraction of pollutants in aqueous solution due to its high surface area, large pores, accessible coordinative unsaturated sites, and excellent chemical and solvent stability. In situ magnetization of MIL-101 microcrystals as well as magnetic solid-phase extraction of PAHs was achieved simultaneously by simply mixing MIL-101 and silica-coated Fe(3)O(4) microparticles in a sample solution under sonication. Such MOF-based magnetic solid-phase extraction in combination with high-performance liquid chromatography gave the detection limits of 2.8-27.2 ng L(-1) and quantitation limits of 6.3-87.7 ng L(-1) for the PAHs. The relative standard deviations for intra- and inter-day analyses were in the range of 3.1-8.7% and 6.1-8.5%, respectively. The results showed that hydrophobic and π-π interactions between the PAHs and the framework terephthalic acid molecules, and the π-complexation between PAHs and the Lewis acid sites in the pores of MIL-101 play a significant role in the adsorption of PAHs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromium Compounds / chemistry*
  • Magnetics*
  • Organometallic Compounds / chemistry*
  • Particle Size
  • Polycyclic Aromatic Hydrocarbons / chemistry
  • Polycyclic Aromatic Hydrocarbons / isolation & purification*
  • Solid Phase Extraction / methods*
  • Surface Properties
  • Water Pollutants, Chemical / chemistry
  • Water Pollutants, Chemical / isolation & purification*

Substances

  • Chromium Compounds
  • Organometallic Compounds
  • Polycyclic Aromatic Hydrocarbons
  • Water Pollutants, Chemical