The paper reports the infinite dilution activity coefficients of a series of polar and nonpolar solutes (alkanes, alcohols, ketones, ethers, aromatic hydrocarbons, halogenated compounds) in 1-ethyl-, 1-butyl-, 1-hexyl-, and 1-octyl-3-methylimidazolium tetrafluoroborate ionic liquids. The data were measured by gas-liquid chromatography at ( 303, 323, and 343) K.