Measurement of activity coefficients at infinite dilution using polar and non-polar solutes in the ionic liquid 1-methyl-3-octyl-imidazolium diethyleneglycolmonomethylethersulfate at T = (288.15, 298.15, and 313.15) K

In this work, the activity coefficients at infinite dilution (γ13∞) for 14 solutes: alkanes, alkenes, an alkyne, cycloalkanes, benzene, and methanol in the ionic liquid 1-methyl-3-octyl-imidazolium diethyleneglycolmonomethylethersulfate were determined by gas + liquid chromatography at the temperatures (288.15, 298.15, and 313.15) K. The ionic liquid had a mass percentage packing greater than 20%. Two columns with different mass percent packing of the ionic liquid were studied at each temperature.The activity coefficient at infinite dilution (γ13∞) for each solute was used to calculate the excess molar enthalpies at infinite dilution (ΔHmE∞). The selectivity value for the hexane/benzene separation was calculated from the γ13∞ and compared to the literature values for other ionic liquids and N-methyl pyrrolidone.Gas + liquid chromatography is a simple, accurate, and reliable method that requires small quantities of the liquid support and solutes.