New Residue Analysis Method for Four Task-Specific Ionic Liquids in Water, Soil and Plants.

With the extensive application of task-specific ionic liquids (TSILs), their environmental impact has attracted increasing attention. However, no studies involving residue analyses of TSILs have been reported in the literature thus far. In the present study, residues of four TSILs ([C 2 NH 2 MIm]BF 4 , [HOEMIm]BF 4 , [HOEMIm]NO 3 , [MOEMIm]BF 4 ) were analyzed by high-performance liquid chromatography-tandem mass spectrometry. The limit of detection of instrument was approximately 10 -15  g. Residual TSILs were extracted from soil and plant samples by the accelerated solvent extraction method. In water, soil and plants, the coefficient of variation was 0.38%-4.43%, and the method detection limits of the four TSILs were lower than 1.40 ng g -1 . These results meet the standards of residue analysis. The present study can provide an analysis method for studying TSIL residues and toxicity in the environment.