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 bis[(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⋯H C pseudohydrogen bonding, π-π 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.