Task-specific solid-phase microextraction based on ionic liquid/polyhedral oligomeric silsesquioxane hybrid coating for sensitive analysis of polycyclic aromatic hydrocarbons by gas chromatography-mass spectrometry

A direct immersion solid-phase microextraction (DI-SPME) approach for gas chromatography-mass spectrometry (GC-MS) based on hybrid fiber coating of ionic liquid and polyhedral oligomeric silsesquioxane (POSS) is presented. To fabricate the task-specific coating for the enrichment of polycyclic aromatic hydrocarbons (PAHs), 1-butyl-3-vinylimidazolium bist(trifluoromethyl)sulfonyl]imide (IL) and POSS were rapidly photoinitiated copolymerized within 5 min on a stainless steel fiber. The high efficient extraction of target analytes can be attributed to a combined result of multiple interactions including the strong C-F center dot center dot center dot H-C pseudohydrogen bonding, pi-pi stacking, hydrophobic force, and molecular sieve effect. A wide linear range (0.04-400 ng L-1) with low detection limits in the range of 0.004 and 0.5 ng L-1 were obtained for PAHs by GC-MS. The applicability of this coupling method was successfully demonstrated by the analysis of trace PAHs in real river water and soil samples, with satisfied recoveries (84.2-108.6%) and relative standard deviations (<8.1%). Compared to the other commercial fiber-based SPME methods, the IL/POSS hybrid coating-based SPME is much cheaper, thermally stable and capable of eliminating possible deleterious effects as well. (C) 2019 Elsevier B.V. All rights reserved.