MEASUREMENT OF THERMODYNAMIC EQUILIBRIA BY CHROMATOGRAPHY

Ioannis Ignatiadis (1) , Marie France Gonnord (1) , Claire Vidal-Madjar (1)

1 X - École polytechnique

After a brief recall of the chromatographic principles, the different applications of gas chromatographic measurements of thermodynamic equilibria were reviewed. Gas and liquid chromatographies are now well known and elegant methods for measuring the physicochemical properties and phase equilibrium thermodynamic constants. Although fundamentally a dynamical method and mostly known as a powerful separation technique, chromatography can be schematized by a succession of equilibria of a chemical species partitioning between a mobile phase and a fixed liquid or solid stationary phase. It can be operated in either infinite dilution or finite concentration conditions and permits to collect a large number of data for calculating molecular interactions for solutes which are either rare or available at the trace level. Gas chromatography permits the measurement of gas adsorption isotherms, gas-liquid equilibria, molecular diffusion and interaction virials. The modelization of successive partition equilibria occuring in the chromatographic column leads to rather simple expressio is of differential enthalpy, entropy, free energy of adsorption or solution, variation of heat capacity, complexation constant, second virial coefficients, gas-solid and gas-liquid isotherms and also binary or ternary equilibria. The possibilities of High Performance-Liquid Chromatography to investigate adsorption from solutions and chemical equilibria are also discussed.

Mots clés: Gas chromatography Liquid chromatography Thermodynamic equilibria Solution and adsorption thermodynamics Gas adsorption isotherms

Domaines: Chimie-Physique [physics.chem-ph]; Chimie théorique et/ou physique

Ioannis Ignatiadis, Marie France Gonnord, Claire Vidal-Madjar. MEASUREMENT OF THERMODYNAMIC EQUILIBRIA BY CHROMATOGRAPHY. Chromatographia, 1987, 23 (3), pp.215-219. ⟨10.1007/BF02311484⟩. ⟨hal-00737634⟩