A novel relationship between GC retention behavior and connectivity indexes.

Abstract

A quantitative structure and property relationships (QSPR) analysis on gas chromatograph relative retention times (GCRT) of polychlorinated biphenyls(PCBs), and their molecular geometrical and topological parameters was carried out. It was found that there was a different change in GCRT depending on solvent accessible surface area(SAS) between the congeners and the isomers. To elucidate the retention characteristics of the isomers, the GCRT were classified in terms of the number of the pair of proximitive Cl and H substituents bonding to the biphenyl skeleton (Npx-Cl and Npx-H). The correlation coefficients were markedly improved between SAS and GCRT ranging in the same category. Next an analysis on the basis of the connectivity indices, which had been derived by Randic, Kier, and Hall, was performed to clarify the topological characteristics for the proximitive positions. It was found that there was a close correlation between the second-order connectivity descriptor, 2 kai , and GCRT for the isomers. On the other hand, from analyses on the correlation between 2 kai and some electrical descriptors, it was revealed that there was a significant correlation between 2 kai and sum of net charge at H substituents (QH).