STRUCTURE-RETENTION CORRELATION ON METHYL PHENYL POLYSILOXANE PHASES IN CAPILLARY GAS-CHROMATOGRAPHY

The selectivity of phenyl methyl polysiloxane phases was examined from the structure-retention correlations of alkanes, alkanols, alkylbenze nes, chlorobenzenes, and polycyclic aromatic hydrocarbons. Selectivity R was obtained from plots of van der Waals volume vs. the difference of their logarithm of capacity ratios, and enthalpy of these compound s was calculated from van't Hoff plot. The enthalpy -DELTAH of polycyc lic aromatic hydrocarbons was greater on phenyl methyl phases compared to those obtained on 100% methyl polysiloxane phase. The retention ti me of homologue series of compounds can be predicted from the selectiv ity or enthalpy, but not for chlorinated benzenes due to the difficult y of the estimation of electron donner effect of chloro group.