Selectivity of Several Liquid Phases for the Separation of Pine Terpenes by Gas Chromatography

Chromatographic retention data and thermodynamic properties of six pine terpenes (α-pinene, β-pinene, camphene, limonene, α-phellandrene and p-cymene) on six different liquid phases, with a wide range of polarity, are reported at temperatures from 80 to 120 °C. The retention behaviour and selectivity of liquid phases for the separation of binary solute systems are discussed in terms of activity coefficients and specific interactions. Solubility parameters for the liquid phases are reported using the regular solution theory and the Takamiya equation and a good correlation between polarity and solubility parameters is observed.