Seven published sets of results on gasâ liquid chromatographic mixed-solvent systems yield data on nearly two hundred ternary liquid systems and these were analysed for conformity with the Scatchardâ Hildebrandâ Floryâ Huggins model of liquid mixtures. Whilst the expected quadratic (ln K R, Ï ) relation applies in most cases, consistent values of solventâ solvent interaction parameters are not obtained when specific soluteâ solvent attractions exist. The use of alkane solutes appears to give constant and meaningful values of these parameters even when specific solventâ solvent interaction occurs. A computed simulation of solute-additive complexing in a solvent medium shows a linear (K R, c) relation at relatively low additive concentration but indicates that any calculation of formation constants by this method must involve very considerable quantitative uncertainty.