Ionic liquids-based crosslinked copolymer sorbents for headspace solid-phase microextraction of polar alcohols.

Halogen-based polymeric ionic liquid (PIL) fibers, which have proved efficient for solid-phase microextraction (SPME) of polar compounds, were with very limited fiber lifetimes. In this work, a novel crosslinked PIL sorbent with satisfactory stability and durability was prepared in situ via crosslinking polymerization processes on microstructured-silver coated stainless steel wire. 1,1'-(1,6-Hexanediyl)bis(1-vinylimidazolium) bibromide ionic liquid was synthesized and used as the crosslinking agent, with 1-vinyl-3-octylimidazolium bromide as monomer. Extraction properties of the fiber for polar alcohols in polar aqueous matrix were examined using headspace SPME (HS-SPME) coupled to gas chromatography-flame ionization detection (GC-FID). Under the optimized extraction and desorption conditions, the established method exhibited high extraction capacity. Wide linear ranges were obtained with correlation coefficients (R) ranging from 0.9947 to 0.9999. Limits of detection were in the range of 0.5-20 μg L⁻¹. Compared with the non-crosslinked PIL fiber, the proposed crosslinked PIL fiber was with higher thermal stability and durability and longer lifetime. Four different liquor beverages were analyzed as real samples and good results were obtained.