This work brings together recent gas chromatography experiments and theory involving multiple sorbing species at finite concentration, and theories for multicomponent polymer solutions by means of the parameter estimation procedure of Part 1. Results quantitatively describe the wide variation in peak retention times that are caused by phase equilibrium and chromatographic interference, the best solution models doing so to within or near experimental error. The chromatographic method is capable of detecting differences and peculiarities in the various polymer solution models in both the accuracy of the calculated retention times and the sensitivities of the calculations to the model parameters. Perturbation chromatography offers some unique capabilities for multicomponent vapor-liquid equilibrium determinations.

Elution times determined from perturbation chromatography experiments are functions of all sorbing species isotherms through the concentration partial derivatives. Measurements at a sufficient number of appropriate compositions along with isotherm models and adjustable parameters allow reduction of the retention time data to VLE by a nonlinear parameter estimation procedure described in this paper. The method can be implemented for both empirical isotherm models, which can be used to minimize model deficiencies, and for theoretical thermodynamic models, which have extrapolation potential and may require fewer parameters.

No abstract