Solvent extraction and supported liquid membrane transport studies for the preferential removal of Am3+ from feeds containing a mixture of Am3+ and Eu3+ was carried out using 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (n-Pr-BTP) as the extractant. Diluent plays an important role in these studies. It was observed that the distribution coefficients deteriorate significantly for both Am3+ and Eu3+ though the separation factors were affected only marginally. The transport studies were carried out at pH 2.0 in the presence of NaNO3 to result in the preferential Am3+ transport with high separation factors. Effect of different experimental parameters, viz, feed composition, stripping agents, diluents of the organic liquid membrane and membrane pore size was studied on the transport and separation behaviour of Am3+ and Eu3+. The supported liquid membrane studies indicated about 85% Am3+ and 6% Eu3+ transport in 6 h using 0.03 M n-Pr-BTP in n-dodecane/1-octanol (7:3) diluent mixture for a feed containing 1 M NaNO3 at pH 2 and a receiver phase containing pH 2 solution as the strippant. Consequently, a permeability coefficient of (1.75 +/- 0.21) x 10(-4) cm s(-1) was determined for the Am3+ transport. Stability of the n-Pr-BTP and its SLM was also studied by carrying out the distribution and transport experiment after different time intervals. (C) 2011 Elsevier B.V. All rights reserved.