Activity coefficients at infinite dilution and gas-liquid partition coefficients (K-L) of 25 organic solutes, including alkanes, alkenes, alkylbenzenes, alcohols, acetonitrile, ethyacetate, acetone, tetrahydrofuran, dichloromethane, trichromethane, and tetrchloromrthane in the ionic liquid 1-octyl-3-methylimidazolium nitrate ([OMIM][NO3]), have been determined by means of gas-liquid chromatography over a temperature range of 303.15-363.15K with the ionic liquid as the stationary phase. From the dependence of experimental activity coefficients, the partial molar excess enthalpies at infinite dilution and the solubility parameters of the organic solutes in the ionic liquid [OMIM][NO3] have been determined. (C) 2012 Elsevier B.V. All rights reserved.