Ma. Al-haj et al., Test analytes for studies of the molecular mechanism of chromatographic separations by quantitative structure-retention relationships, ANALYT CHEM, 71(15), 1999, pp. 2976-2985
Three model series of nonionized in water analytes are proposed for objecti
ve interlaboratory comparisons of effects on chromatographic separations of
the stationary and the mobile phases by means of the analysis of quantitat
ive structure-retention relationships (QSRR), Each series was designed spec
ifically for a given general QSRR model by selecting the analytes whose pro
perties were well reflected by the respective structural descriptors. Rules
of a meaningful chemometric analysis were observed, and the structural inf
ormation content was compromised with the length of analyte series. Three Q
SRR models were verified and are recommended for studies of molecular mecha
nism of chromatographic retention: the reduced linear solvation energy rela
tionship-based model of Abraham, a model employing structural descriptors f
rom molecular modeling, and a model correlating retention to the 1-octanol-
water partition coefficient, log P. All the models were demonstrated to pro
tide reliable QSRR equations for five sets of diverse retention data. These
equations discriminate quantitatively individual chromatographic systems a
nd are interpretable in straight forward chemical categories. In view of QS
RR analysis, the retention processes clearly emerge as the net effects of f
undamental intermolecular interactions involving the analyte and the compon
ents of chromatographic systems.