Measurements of activity coefficients at infinite dilution in bisphenol-a-polycarbonate were carried out for a series of alkanes (C-8,C-9,C10C12), alcohols (C-3-C-10) and aromatics (toluene, ethylbenzene, propylbenzene, o-, m-, p-xylene, chlorobenzene, o-dichlorobenzene) at 160 degrees C, 180 degrees C and 200 degrees C using the inverse gas chromatography. Applying a gravimetric method, the solubilities of different solvents (chlorobenzene, toluene, ethylbenzene, m-xylene, p-xylene and mesitylene) in the same polymer were measured. To model the absorption data the SAFT equation of state was used. For this purpose the pure-component parameters of the polymer had to be adjusted to the binary data of one polycarbonate-solvent system. Using these parameters for the polymer, the experimental data of the other systems could be described well, too.