In situ hydrothermal growth of metal-organic framework 199 films on stainless steel fibers for solid-phase microextraction of gaseous benzene homologues.

TLDR: The first example of the utilization of MOFs for solid-phase microextraction (SPME) is reported, with MOF-199 with unique pores and open metal sites employed as the coating for SPME fiber to extract volatile and harmful benzene homologues.

Abstract: Metal−organic frameworks (MOFs) have received great attention due to their fascinating structures and intriguing potential applications in various fields. Herein, we report the first example of the utilization of MOFs for solid-phase microextraction (SPME). MOF-199 with unique pores and open metal sites (Lewis acid sites) was employed as the coating for SPME fiber to extract volatile and harmful benzene homologues. The SPME fiber was fabricated by in situ hydrothermal growth of thin MOF-199 films on etched stainless steel wire. The MOF-199-coated fiber not only offered large enhancement factors from 19 613 (benzene) to 110 860 (p-xylene), but also exhibited wide linearity with 3 orders of magnitude for the tested benzene homologues. The limits of detection for the benzene homologues were 8.3−23.3 ng L−1. The relative standard deviation (RSD) for six replicate extractions using one SPME fiber ranged from 2.0% to 7.7%. The fiber-to-fiber reproducibility for three parallel prepared fibers was 3.5%−9.4% (RSD)...