CHEMOMETRIC CLASSIFICATION OF THE SOLVENT PROPERTIES (SELECTIVITY) OFCOMMONLY USED GAS-CHROMATOGRAPHIC STATIONARY PHASES

Abraham's solvation parameter model was used to characterize the solve nt properties of 33 stationary phases in terms of their capacity for s pecific intermolecular interactions at 121.4 degrees C. The capacity o f the phases for dispersion, orientation, induction, and hydrogen-bond base interactions, combined with solvent cohesion (ease of cavity for mation) were important in defining their behavior. The capacity for pi - and n-electron pair acceptor interactions was less important and non e of the phases possessed a significant capacity for solvent hydrogen- bond acid interactions. Principal component analysis and hierarchical clustering techniques were used to classify the phases by their simila rity for specific intermolecular interactions. These methods provide a visual means of quantitatively comparing the properties of the statio nary phases and a mechanism to develop a short list of phases able to represent the range of properties available in the larger data set.