In this work, activity coefficients at infinite dilution (gamma(infinity)(13)) have been obtained for 19 polar and non-polar organic solutes in the form of n-alkanes, cycloalkanes, 1-alkenes, 1-alkynes, aromatic compounds, and ketones in the ionic liquid methyl(trioctyl)ammonium thiosalicylate by gas-liquid chromatography at three different temperatures, i.e. T = (303.15, 313.15, and 323.15) K. Two columns with different phase loadings of the ionic liquid in the stationary phase (25% and 30%) were employed to obtain gamma(infinity)(13), values at each temperature investigated. Partial molar excess enthalpies at infinite dilution (Delta H-1(E,infinity)) were calculated for each of the solutes from the temperature dependency of the gamma(infinity)(13) values for the temperature range in this study. Selectivity values at infinite dilution (S-ij(infinity)) were computed from the gamma(infinity)(13) values to screen the potential candidacy of the ionic liquid for the separation of n-hexane/benzene mixtures. The results from this study have been compared to those available for several other classes of ionic liquids and commercial solvents employed in solvent-enhanced industrial separation processes. (C) 2011 Elsevier Ltd. All rights reserved.