Solute interaction with nonpolar stationary phases in liquid chromatography is examined on the basis of the solvophobic theory. The chromatographic process is viewed as a reversible association of the solute with the hydrocarbonaceous ligands of bonded phases. A detailed analysis of the effect of the solvent on this process yields an expression for the capacity factor with essentially no adjustable constants. The theory satisfactorily accounts for the factors affecting solute retention under a wide range of experimental conditions. It makes possible the characterization of the solvophobic (eluent) strength of mixed solvents having different composition and the evaluation of the various solvophobic forces representing incremental values of the logarithm of the capacity factor. The wide applicability of nonpolar stationary phases (reversed phases) in liquid chromatography is demonstrated by the rapid separation of biogenic acids and bases on octadecylsilica columns with neat aqueous elements.