PREDICTION OF GAS-CHROMATOGRAPHIC RETENTION TIMES AND RESPONSE FACTORS USING A GENERAL QUANTITATIVE STRUCTURE-PROPERTY RELATIONSHIP TREATMENT

A general yet effective QSPR treatment on 152 individual structures in corporating a wide cross section of classes of organic compounds has g iven good six-parameter correlations for gas chromatographic retention times (R(cv)(2) = 0.955 for t(R)) and for Dietz response factors (R(c v)(2) = 0.881 for RF(Dietz)) The statistical treatment utilized the CO DESSA program code to find the best multiparameter correlations from s ubsets of given size within larger sets of molecular descriptors. In t he case of t(R), the most important descriptors are alpha polarizabili ty and the minimum valency at an H atom, describing the dispersional a nd hydrogen-bonding interaction between the compound studied and the g as chromatographic medium, respectively. In the case of RF, the most i mportant descriptors are the relative weight of ''effective'' carbon a toms and the total molecular one-center one-electron repulsion energy in the molecule. It has thus been demonstrated that with just six-para meter equations, in each case, the retention times and response factor s for compounds that are unknown, unavailable, or not easily handled ( toxic, odorous, etc.) can now be predicted with a considerable degree of confidence.