Facile fabrication of ionic liquid doped polycarbazole coating for the headspace solid-phase microextraction of some environmental pollutants

• A novel polycarbazole (PCz)-ionic liquid (IL) composite coating is fabricated.
• ILs promote the electrodeposition of poor-conductive PCz and enhance its performance.
• The resulting fiber combines the good extraction of IL and high stability of PCz.
• The fiber shows good extraction property to environment pollutants.

A novel polycarbazole (PCz)–ionic liquid (IL, i.e. 1-hydroxyethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, [HOEMIm][NTf2]) composite coating (PCz-IL) was fabricated by electrodeposition. The IL could facilitate the electrodeposition of poor-conductive PCz and a more porous coating was obtained. The composite coating exhibited enhanced extraction capacity for some environmental pollutants (i.e. o-chlorotoluene, p-bromotoluene, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene), as they could interact through π-π and hydrophobic interactions. Compared with [HOEMIm][NTf2] coated fiber, some other PCz-IL fibers (here IL=1-hydroxyethyl-3-methylimidazolium hexafluorophosphate and 1-methyl-3-octylimidazolium hexafluorophosphate) and commercial fibers (i.e. polydimethylsiloxane and polyacrylate), the PCz-IL fiber showed better performance. It was used for the determination of the environmental pollutants by coupling with gas chromatography, the limits of detection were 47.8–65.9 ng L−1 under the optimized conditions and the linear ranges were 0.1–500 μg L−1 with correlation coefficients above 0.9947 for different compounds. The relative standard deviations (RSDs) were 3.4–4.6% for five successive extractions with single fiber, and the RSDs for inter-fiber were 6.5–10.4% (n=5). The fiber was successfully applied to the detection of real samples and the recoveries for standards added were 88.6–108.8% with RSDs below 9.7%.

PCz coating (a) and PCz-[HOEMIm][NTf2] coating (b) both present cauliflower shape, the later has many nanoscale particles and thus exhibits larger adsorption capacity.Figure optionsDownload as PowerPoint slide