Researchers at the CAS Key Laboratory of Chemistry of Northwest Plant Resources have introduced a novel preparation protocol of solid-phase microextraction (SPME) fiber using stainless steel wire as support.

The stainless steel wire was firstly coated with silver layer and then functionalized with dithiol, which acted as the chain transfer agent in polymerization reaction. Ionic liquid of VOIm+PF6− was employed as monomer and polymerized in situ on the surface of stainless steel wire. Extraction performance of the poly(VOIm⁺PF6⁻)-coated fiber was tested with both headspace and direct-immersion modes. In combination with the microstructured silver layer, satisfactory results were obtained with the proposed PIL fiber. The performance of the fiber was also compared with other IL-coated SPME fiber for the same model analytes. The new fiber showed acceptable sensitivity and extraction efficiency.

Based on the preparation procedures in this work, self assembled dithiol compounds on silver can be used as efficient chain transfer agent for universal monomer radical polymerization. So “designable fibers” with different functional coatings can be obtained through changing the combination of cation and anion of ILs, or other kinds of monomers based on the proposed low-cost method.

The work has received support from the National Natural Science Foundation of China. The findings have been published in J. Chromatogr. A (J. Chromatogr. A 1218 (2011) 7758– 7764).

J. Chromatogr. A Paper

Preparation schema of the poly(VOIm+PF6−)-coated fiber. (a) Anion exchange of the IL and (b) functionalization of the stainless steel wire and the polymerization.