Global linear solvation energy relationships for retention prediction in reversed-phase liquid chromatography

A global linear solvation energy relationship (LSER) that simultaneously mo dels retention in reversed-phase liquid chromatography as a function of bot h solute LSER descriptors and mobile phase composition has been derived fro m both the local LSER model and the linear solvent strength theory (LSST). At most only twelve coefficients are required to establish the global LSER model. Many more coefficients would be required if the same data set were m odeled using the local LSER model. The global LSER was tested with the rete ntion data obtained in acetonitrile-water, tetrahydrofuran-water, and metha nol-water mobile phases each at four or five mobile phase compositions for a large number of highly variegated solutes. Although fewer regression coef ficients are used in a global LSER fit than in a series of local LSER fits for the same data, the results show that the goodness-of-fit of the global LSER is as good as that obtained in the local LSERs, The results also show that the residuals of the LSST its are smaller than those of both the local LSER fits and the global LSER fit and that the residuals of a global LSER fit result mainly from the local LSER model and are not due to the LSST mod el. (C) 1999 Elsevier Science B.V. All rights reserved.