Affiliation: | a Universidad Nacional de La Plata, Facultad de Ciencias Exactas, Div. Química Analítica, 47 Esq. 115, 1900 La Plata, Argentina b Universidad Nacional de La Plata, Facultad de Ciencias Exactas, Departamento de Física, 1900 La Plata, Argentina c CIDEPINT, 52 e/121 y 122, 1900 La Plata, Argentina |
Abstract: | The contributions to the free energy change involved in the chromatographic retention of n-alkanes, which are functions of the solute chain length, are discussed with the aid of recent advances in chain statistics. In the context of a simplified theoretical analysis, a discussion is promoted on the molecular nature of the observed slight deviations from linearity of ln tR′ vs. n. A non-linear function ln tR′(n) is derived from the application of the generalized Van der Waals fluid partition function to the liquid stationary phase. The excluded volume, particularly its dependence on n, is analyzed through the theory of Flory for dilute solutions of chain molecules. |