The capillary column inverse gas chromatography technique was used to determine diffusivity and solubility data for several solutes in a poly(styrene-co-acrylonitrile) random copolymer (SAN). Both infinite dilution and finite concentration experiments were conducted using an IGC-mass spectrometer (IGC-MS) technique that combines the performance of the gas chromatography technique with the resolution of the mass spectrometer detector. Thirteen solutes were studied to obtain thermodynamic and diffusion coefficients at infinite dilution. Finite concentration experiments were conducted with toluene up to 10 wt.% concentration. Pseudo-binary experiments were also conducted in which a trace amount of hexane was injected in a mixture of toluene and SAN. (C) 2008 Elsevier Ltd. All rights reserved.