Sorbent coatings for solid-phase microextraction based on mixtures of polymeric ionic liquids

Four polymeric ionic liquids based on two different cations, poly(1-vinyl-3-hexylimidazolium) and poly(1-vinyl-3-hexadecylimidazolium), combined with two different anions, bis[(trifluoromethyl)sulfonyl]imide (NTf2-) and chloride (Cl-), were combined in various weight percentages and used as sorbent coatings for solid-phase microextraction gas chromatography (SPME-GC). The selectivity of the fiber coatings for 12 test analytes was examined. The extraction efficiency of n-alcohols increased with an increase in the weight percentage of chloride ion in the sorbent coating. The ability to tune the interactions between the coating material and the analytes was exploited and resulted in distinct changes in the limits of detection for hydrogen-bonding analytes with varying chloride ion content in the sorbent coating.