Dispersive liquid-liquid microextraction (DLLME) using ionic liquid (IL) as extraction solvent was developed as a new approach for the determination of four pyrethroid pesticides in environmental water and soil samples. High-performance liquid chromatography with ultraviolet detection (HPLC-UV) was employed on chromatographic analysis. The method is rapid, easy to operate and enviromentally-friendly. The highly toxic chlorinated solvent was replaced by the IL 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]), in which high extraction recovery and enrichment factors were obtained. The effects of IL volume, type and volume of disperser solvent, salt addition, pH and extraction time were investigated and optimized. Under optimum conditions, the method showed good linear response with correlation coefficient (R²) values in the range of 0.9943 to 0.9986. Relative standard deviation (RSD) varied from 3.9 to 10.1%. Enrichment factor, limit of detection and recovery ranged from 260 to 319, 0.94 to 1.97 µg L-1 and 89 to 98%, respectively. For real water samples, RSD ranged from 3.8 to 10.8%, and recovery from 83 to 99%. For soil sample analysis, RSD and recovery ranged from 3.7 to 8.9% and 88 to 98, respectively.
ionic liquid dispersive liquid-liquid microextraction; pyrethroid pesticides; HPLC-UV; environmental sample
