Extraction of poly aromatic hydrocarbons (PAHs) using magnetic ionic liquids (MILs) as extractive materials from water samples

Herein two magnetic ionic liquids (MILs), [P₆₆₆₁₄]₂[CoCl₄] and [P₆₆₆₁₄]₃ [DyCl₆], were synthesized and evaluated as extractive materials in a micro liquid extraction procedure (MLE) to remove polycyclic aromatic hydrocarbons (PAHs) present in water samples. The extraction capacity of evaluated PAHs was studied at different conditions such as pH, extraction time, MIL mass, PAH concentration and ionic strength. Both synthesized MILs demonstrated successful extraction of the five evaluated PAHs. Optimal extraction conditions were achieved at pH = 2, 60 min, and 7.5 % NaCl and 15 mg for [P₆₆₆₁₄]₂[CoCl₄] and 10 % NaCl, and 100 mg of [P₆₆₆₁₄]₃[DyCl₆] for each of PAH. Finally, recovery and reuse of the MILs was evaluated. In this study, only [P₆₆₆₁₄]₂[CoCl₄] was recovered successfully without the presence of any PAH and used successfully in future extractions. Recovered [P₆₆₆₁₄]₂[CoCl₄] was used for five consecutive extractions with an extraction efficiency of the Pyrene above 99 %. These MILs effectively extracted five PAHs from aqueous samples and proved to be recyclable for up to five extraction cycles. These MILs have a high potential to be employed as extractive materials for remediation purposes.