Dispersive liquid–liquid microextraction of pesticides and metabolites from soils using 1,3‐dipentylimidazolium hexafluorophosphate ionic liquid as an alternative extraction solvent

In this work, the use of the ionic liquid ( IL ) 1,3‐dipentylimidazolium hexafluorophosphate ([PPIm][PF 6 ]) as an alternative extractant for IL dispersive liquid–liquid microextraction ( IL ‐ DLLME ) of a group of pesticides and metabolites (2‐aminobenzimidazole, carbendazim/benomyl, thiabendazole, fuberidazole, carbaryl, 1‐naphthol, and triazophos) from soils is described. After performing an initial ultrasound‐assisted extraction ( USE ), the IL ‐ DLLME procedure was applied for the extraction of these organic analytes from soil extracts. Separation and quantification was achieved by high‐performance liquid chromatography ( HPLC ) with fluorescence detection ( FD ). Calibration, precision, and accuracy of the described USE ‐ IL ‐ DLLME ‐ HPLC‐FD method using [PPIm][PF 6 ] as an alternative extractant was evaluated with two soils of different physicochemical properties. Accuracy percentages were in the range 93–118% with RSD values below 20%. A comparison of the performance of [PPIm][PF 6 ] versus that of the so‐common 1‐hexyl‐3‐methylimidazolium hexafluorophosphate ([HMIm][PF 6 ]) was accomplished. Results indicate a comparable extraction efficiency with both IL s, being slightly higher with [HMIm][PF 6 ] for the metabolite 2‐aminobenzimidazole, and slightly higher with [PPIm][PF 6 ] for triazophos. In all cases, LOD s were in the low ng/g range (0.02–14.2 ng/g for [HMIm][PF 6 ] and 0.02–60.5 ng/g for [PPIm][PF 6 ]). As a result, the current work constitutes a starting point for the use of the IL [PPIm][PF 6 ] for further analytical approaches.