Activity coefficients at infinite dilution (gamma(infinity)) values are of great importance when designing separation processes like distillation, liquid-liquid extraction and gas stripping. In this study the gamma(infinity) values were determined for four compounds in water that are present in bio-oil. Henry's law constants (H-12), Partial molar excess enthalpies at infinite dilution ((H) over bar (E,infinity)(i)) and air-water partition coefficients (K-aw) are also reported. The measurements were performed using inert gas stripping equipment (dilutor) in the 298-340 K temperature range. Mass transfer study was also performed to investigate the equilibrium between the solution and the gas leaving the cell. (C) 2015 Elsevier B.V. All rights reserved.