Retention vs van der walls volume,pi-energy and hydrogen-bonding energy effects and enthalpy in liquid chromatography

Summary The logarithm of capacity ratios (logk’) of alkanes, alkyl alcohols, alkylbenzenes, halogenated benzenes and polyaromatic hydrocarbons are measured in reversedphase liquid chromatography at several temperatures using an octadecyl-bonded silica gel as the packing and acetonitrile/water mixtures as the eluent. The Δ (logk’) values are related to their van der Waals volumes, pi-energy and hydrogen-bonding energy effects and their enthalpies. The difference between the observed capacity ratios and the capacity ratios predicted from van der Waals volumes, pi-energy and hydrogen-bonding energy effects can be explained due to enthalpy effect of larger molecular size compounds. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984