In situ growth of IRMOF-3 combined with ionic liquids to prepare solid-phase microextraction fibers.

A superior solid-phase microextraction (SPME) fiber-coating material, IRMOF-3@ILs/PDMS, was prepared by the in situ growth of IRMOF-3 onto stainless-steel wires and protection with ionic liquids (ILs) and polydimethylsiloxane (PDMS). The ILs can efficiently prevent the substantial cracking of IRMOF-3 caused by moisture, and a thin PDMS film can protect the IRMOF-3@ILs material to achieve a much better extraction efficiency as well as excellent resistance to high temperature and high humidity. This IRMOF-3@ILs/PDMS coating possessed a porous structure, a rough surface and an increased lifespan (by at least 100 times) compared with that of IRMOF-3. The coating was evaluated by analyzing four polycyclic aromatic hydrocarbons (PAHs) in water, and good precision (<7.7%), low detection limits (12.0-15.4 ng L(-1)), and wide linearity (50-20,000 ng L(-1)) were achieved under the optimized conditions. The fiber was successfully applied to the sensitive analysis of PAHs in rainwater by coupling it with gas chromatography-mass spectrometry (GC-MS).