Solid-phase microextraction (SPME) is popular in trace analysis due to its advantages such as absence of organic solvent, easiness to on-line coupling and high sensitivity. To date, almost all kinds of traditional and newfound materials have been used as coating materials for SPME fibers. ILs have made significant contributions to the development of analytical chemistry. Their physical and chemical properties can be tuned by varying the cation or anion.

Researchers at Lanzhou Institute of Chemical Physics (LICP) of the Chinese Academy of Sciences and Jinan University have tuned the properties of ionic liquid based on the modification of its anion via metathesis reaction. The proposed IL, with 2-naphthalene-sulfonate as building anion unit, exhibited enhanced hydrophobicity and aromaticity based on the studies of its octanol/water distribution coefficient and partition coefficients of PAHs. Extended subsequent application was investigated with PAEs as model analytes. High extraction efficiency was also obtained. Hair spray and nail polish were used as real samples and some PAEs were quantified in them.

Preparation schema of the poly(VOIm+NapSO3−) coated fiber.

Performance of the proposed fiber indicated that modification of anions was another efficient process to impart special functionalizations to ILs.

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 1227 (2012) 54– 59).