A new amide functionalized ionic liquid, N,N-dioctyl-2-(3-methylimidazolium)acetamide bis(trifluoromethanesulfonyl)imide (DOAImNTf(2)), was synthesized and characterized by IR, NMR and mass spectroscopy. The extraction behavior of Pu(IV), U(VI) and Am(111) from nitric acid medium by a solution of DOAImNTf(2) in the room temperature ionic liquid, 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (C(n)mimNTf(2)), was studied as a function of concentration of nitric acid and DOAlmNTf2. The distribution ratio of Pu(IV) in DOAImNTf(2)/C(4)mimNTf(2) decreased with increase in the concentration of nitric acid, reached a minimum at 4-5 M nitric acid followed by increase. In contrast to this, the distribution ratio of U(VI) and Am(III) in DOAImNTf(2)/C(4)mimNTf(2) was insignificant at all nitric acid concentrations. Consequently, the separation factor of Pu(IV) from other actinides, achieved with the use of DOAImNTf(2)/C(4)mimNTf(2), was significantly high ranging from 40 to 4000 depending upon the conditions employed for extraction. The stoichiometry of Pu(IV)-DOAImNTf(2) was determined by the slope analysis of extraction data. The task specific nature of DOAImNTf(2) was also confirmed by the negligible extraction of fission products from nitric acid medium spiked with high-level liquid waste (155 Gwd/Te). The viscosity of ionic liquid phase at various temperatures was determined and the results are reported in this paper. (C) 2012 Elsevier B.V. All rights reserved.