Role of Temperature in the Behavior of PAHs in Micellar Liquid Chromatography. Thermodynamic Aspects

摘要

Thermodynamic properties (enthalpy and entropy) of the transfer of polynuclear aromatic hydrocarbons from the bulk aqueous mobile phase to the stationary phase and from the bulk aqueous phase to the micellar phase are determined. It is shown that withincreasing hydrophobicity, the solute has a greater affinity for the modified stationary phase than for the micellar phase. Furthermore, the influence of temperature on the selectivity of the separation is studied; it is shown that increasing the temperature increases the selectivity of the separation, especially for the most hydrophobic polynuclear aromatic hydrocarbons. However, the addition of alcoholic modifiers to the mobile phase is necessary to obtain the best separations and shortest analysis times.