In situ room-temperature fabrication of a covalent organic framework and its bonded fiber for solid-phase microextraction of polychlorinated biphenyls in aquatic products

Abstract

Development of new coating materials for solid-phase microextraction (SPME) along with facile methods for the fabrication of their firm coatings on SPME fibers is urgently needed for sample preparation. Here we show room-temperature preparation of a novel covalent organic framework (COF) TFPB-BD from 1,3,5-tris-(4-formylphenyl)benzene (TFPB) and benzidine (BD), and in situ room-temperature fabrication of a TFPB-BD bonded fiber for SPME of polychlorinated biphenyls (PCBs). TFPB and BD were employed as monomers for in situ growth of a new COF TFPB-BD on an amino-functionalized stainless steel fiber at room temperature. The developed TFPB-BD bonded fiber was used to develop a new SPME method for GC/MS/MS determination of trace PCBs in aquatic products. The developed analytical method gives enhancement factors of 4471–7488 and detection limits of 0.07–0.35 ng L⁻¹. The precision (RSD) for six replicate determinations of 100 ng L⁻¹ PCBs with a single fiber and the fiber-to-fiber reproducibility for three parallel prepared fibers was in the range of 3.8–8.8%, and 5.3–9.7%, respectively. The recoveries for spiked 1.0 μg kg⁻¹ PCBs in aquatic products were 87.1–99.7%.