Classification and comparison of capillary columns by determination of the solution enthalpy of polar and non polar probes

The behaviour and separation characteristics of capillary columns containing different stationary phases (bonded methyl- and methylphenylsiloxanes and polyglycols, and carbon layer and porous polymer) were classified and compared by measuring the values of the solution enthalpy ΔHs of n-alkanes and 1-alcohols at various temperatures. The difference in ΔHs values between straight-chain 1-alcohols and n-alkanes with the same number of carbon atom (ΔΔHs) does not change with changing temperature when gas-liquid partition stationary phases are used, but depends on the column composition and polarity and therefore permits to evaluate the influence of polarity on the solute-solvent interaction. The trend of the ΔΔHs values is correlated with that of the ΔC parameter and with the McReynolds' polarity constants.