Abstract:

A novel solid-phase microextraction fiber was prepared via simple adhesion process. Fused-silica fiber was used as supporting substrate and the cucurbit[7]uril/Eu coordination polymers induced by [CdCl₄]^2- anion was affixed onto the surface of fused-silica fiber with high-temperature epoxy resin as a sorbent coating. The SPME coating was characterized by scanning electron microscopy and thermal analysis. Coupled to gas chromatography, the fiber was used to extract polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Analytical performances of the proposed method were investigated under the optimum extraction conditions (extraction temperature, 75 ℃; mass concentration of NaCl, 200 g/L; extraction time, 40 min; desorption time, 2 min; desorption temperature, 250 ℃) compared with commercial fibers for the same analytes. For the seven PAHs (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene), good linearity was obtained ranging from 1 μg/L to 1000 μg/L. Limits of detection were 0.29-2.09 μg/L with the RSDs no more than 8.6%. The established SPME-GC method was applied to determine the spiked PAHs in real river water samples and satisfactory results were obtained with recoveries between 97.2% and 109.0%. Under the optimal conditions, the extraction effect of home-made coating was similar to the commercial PDMS (polydimethylsiloxane) coating, which further confirmed its potential in the solid-phase microextraction.

Key words: cucurbit[7]uril coordination polymers, environmental water, gas chromatography (GC), polycyclic aromatic hydrocarbons, solid-phase microextraction (SPME)