Solute Retention in Column Liquid Chromatography. V. the Column Dead Volume

Abstract

Methods of determination of the column void volume with two homologous series of solutes (alkyl-substituted aromatic hydrocarbons and phenyl-substituted aliphatic alcohols) are considered in terms of correlation coefficients r of plots of log V'_R against carbon number over the temperature range 10[ddot]-30[ddot]C. The homologous series methods provide self-consistent fits as well as temperature-invariant data for the aromatic hydrocarbons, but not for the alcohols, for which a mixed retention mechanism is said to obtain. A new graphical method of determining the best-fit value of V_A is introduced that makes use of plots of r against assumed V_A. In contrast to work reported elsewhere by others, each of the series of compounds studied in this work clearly exhibits a maximum. Those for the aromatic hydrocarbons are temperature-invariant; however, this is not so for the alcohols, which is taken as evidence of thermal and/or multiple sorption interactions of these solutes with the stationary phase.