Fluorine-functionalized conjugated microporous polymer as adsorbents for solid-phase extraction of nine perfluorinated alkyl substances.

Perfluorinated alkyl substances (PFASs) are persistent, toxic, ubiquitously distributed, and bioaccumulated substances, which have attracted increasing concern. To investigate the environmental effects of PFASs, there is a need to develop a sensitive, rapid, and efficient method for detecting trace level PFASs. In this study, a conjugated microporous polymer (CMP) with loading of fluorine, fabricated by Sonogashira-Hagihara cross-coupling, was exploited as a solid-phase extraction (SPE) adsorbent. The prepared fluorine-functionalized CMP (FCMP), which showed a large surface area of 1089 m·g, high porosity, and good chemical stability, was used to extract PFASs from water samples. The adsorption mechanism was investigated using a sorption isotherm model, and the main interactions were fluorous and hydrophobic affinity. The FCMP-based SPE combined with high-performance liquid chromatography-tandem mass spectrometry achieved low limits of detection (0.19-0.97 ng·L), wide linear range (2-1600 ng·L), and good reproducibility (3.4%-12.9%) under the optimal conditions. Furthermore, the approach was utilized for the analysis of three water samples (snow, river water, and irrigation water) to evaluate its reliability, and satisfactory recovery (70.5%-127.5%) was obtained. Thus, FCMP was feasible SPE adsorbents for the selective extraction of PFASs.