Imidazolium zinc-containing ionic liquids (IL), [1-R-3-R'-imidazolium] alkyl sulfate-ZnCl2 (R and R '= H or alkyl), were very effective for removing nitrogen from a model fuel containing quinoline, indole, or acridine in n-heptane. The interaction of EtSO 4 and ZnCl 2 (EtSO 4) with a heterocyclic N compound was studied theoretically. Zn-containing IL, [EMIm] ZnCl 2 (EtSO 4) used to recover quinoline were successfully regenerated using diethyl ether as the back extractant.