Fabrication of robust polyimide-coated solid phase microextraction fibers for efficient extraction of fifteen polycyclic aromatic hydrocarbons from environmental water

A novel supporting material was developed by pulling melted glass onto stainless steel, providing a mechanically robust and chemically stable substrate. A polyimide-coated fiber for solid-phase microextraction (SPME) was then fabricated using a simple dipping method. The strong interactions between the polyimide coating and analytes, attributed to abundant unshared electron pairs in the p orbitals of O and N atoms, as well as π electrons in the C[double bond, length as m-dash]O bond and benzene ring, contributed to the high extraction efficiency for sixteen polycyclic aromatic hydrocarbons. The developed polyimide-coated fiber-based SPME method, coupled with gas chromatography-flame ionization detection, exhibited low limits of detection (0.11-1.23 μg L^-1) and a wide linear range (1-500 μg L^-1) for polycyclic aromatic hydrocarbons in water samples. The method demonstrated excellent repeatability, with single-fiber repeatability ranging from 2.9% to 6.9% and fiber-to-fiber reproducibility between 3.9% and 11.5%. The recoveries of the analytes were between 82.7% and 107.2%. Additionally, the fiber exhibited outstanding durability, maintaining its extraction performance after more than 150 uses. The developed method was successfully applied for the determination of polycyclic aromatic hydrocarbons in river, pond, and sewage water samples, highlighting its potential as a sensitive, reliable, and cost-effective tool for environmental analysis.