The study of solute-polymeric liquid solvent interaction contributes to the understanding of the fundamental principles of chromatography since liquid polymers are often used as stationary phases in gas chromatography (GC) and high-performance liquid chromatography (HPLC). The knowledge of how a polymeric stationary phase interacts with different types of compounds helps researchers to select and synthesize the right phase for successful separation of mixtures in a time-efficient manner. The development of a simple, cost effective, and time-efficient method for studying solute-solvent interaction can aid significantly the ever-expanding applications of chromatography. Ln this work, a new approach, solid phase microextraction (SPME), is used for investigations of activity coefficients of the McReynolds probe solutes in selected liquid polymers. The probe solutes are absorbed by an immobilized liquid polymer phase coated on the outside surface of a fused silica fiber, and quantitated by a GC technique using a commercially available GC column. The research in this study shows that activity coefficients measured by SPME are equivalent to those by the commonly used GC method. This new method eliminates the need to prepare a GC column using the polymer of interest as in the GC method and, thus, significantly simplifies the whole measuring process. it also allows convenient investigation of the prepared coating by other surface and spectroscopic techniques.