Oxidative polyacrylonitrile nanofiber-based solid-phase microextraction coatings via wrapping strategy for polychlorinated biphenyls determination coupled to GC-MS.

A straightforward approach to fabricating robust and versatile solid-phase microextraction (SPME) fibers is crucial for the extensive research and application of this notable sample preparation technique. Herein, we proposed a strategy for preparation of oxidative polyacrylonitrile (O-PAN) and O-PAN/ZIF-67 nanofiber-based SPME coatings by wrapping an electrospinning membrane on the stainless-steel wire, following with thermal oxidation at 300 °C. The shrinkage of membrane during thermal treatment resulted in the nanofibers being securely affixed to the stainless-steel wire, thereby creating a robust nanofiber-based SPME fiber. Furthermore, the characterizations results indicated that the thermal oxidation significantly enhanced the generation of oxygen-/nitrogen-containing groups within the nanofibers, which were conducive to the adsorption for the analytes. Given the exceptional properties, the proposed O-PAN/ZIF-67 coating was applied to extract and analyze polychlorinated biphenyls (PCBs) pollutants coupled with GC-MS, and exhibited superior extraction performances. The proposed analytical method presented a wide linear range spanning concentrations from 0.5 to 2500 ng L, with a low detection limit ranging between 0.029 and 0.093 ng L. Additionally, it demonstrated good precision, as evidenced by a relative standard deviation of 4.5 %-8.1 %, and was effectively utilized for the analysis of real water samples. This study introduced a novel, simple, and versatile methodology for the fabrication of nanofiber-based SPME coatings, offering a significant advancement in the field.