Bis(trifluoromethanesulfonyl)imide-based ionic liquids grafted on graphene oxide-coated solid-phase microextraction fiber for extraction and enrichment of polycyclic aromatic hydrocarbons in potatoes and phthalate esters in food-wrap

•NTf2−-based PILs-GO SPME fibers were prepared by on-fiber anion exchange.•NTf2−-based PILs exhibited more hydrophobic than Br−-based PILs.•We investigated the partition coefficients of analytes between different ILs-GO fibers and aqueous solution.•The proposed SPME fiber was successfully used to extract PAHs and PAEs in real samples.

A class of novel, environmental friendly ionic liquids (ILs) were synthesized by on-fiber preparation strategy and modified on graphene oxide (GO)-coated stainless steel wire, which was used as a solid-phase microextraction (SPME) fiber for efficient enrichment of polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs). Surface characteristic of the ILs and polymeric-ILs (PILs) fibers with the wave-structure were inspected by scanning electron microscope. The successfully synthesis of bis(trifluoromethanesulfonyl)imide (NTf2−)-based ILs were also characterized by energy dispersive spectrometer analysis. Through the chromatograms of the proposed two ILs (1-aminoethyl-3-methylimidazolium bromide (C2NH2MIm+Br−), C2NH2MIm+NTf2−) and two PILs (polymeric 1-vinyl-3-hexylimidazolium bromide (poly(VHIm+Br−)), poly(VHIm+NTf2−))-GO-coated fibers for the extraction of analytes, NTf2−-based PIL demonstrated higher extraction capacity for hydrophobic compounds than other as-prepared ILs. Analytical performances of the proposed fibers were investigated under the optimized extraction and desorption conditions coupled with gas chromatography (GC). Compared with the poly(VHIm+Br−)-GO fiber, the poly(VHIm+NTf2−)-GO SPME fiber brought wider linear ranges for analytes with correlation coefficient in the range of 0.9852–0.9989 and lower limits of detection ranging from 0.015–0.025 μg L−1. The obtained results indicated that the newly prepared PILs-GO coating was a feasible, selective and green microextraction medium, which could be suitable for extraction and determination of PAHs and PAEs in potatoes and food-wrap sample, respectively.

Graphical abstractDifferent ILs and PILs modified onto the GO-coated stainless steel wire were optimized and we selected the NTf2−-based PIL-GO SPME fiber to detect PAHs in potatoes and PAEs in food-wrap.Figure optionsDownload full-size imageDownload as PowerPoint slide