EFFECT OF ESTER MOLECULAR-STRUCTURE AND COLUMN TEMPERATURE ON THE RETENTION OF 8 ESTERS IN GAS-CHROMATOGRAPHY

An experimental design has been used to study the effect of column temperature on the gas chromatographic retention of eight para-hydroxy benzoic esters. A rapid procedure has been developed to reduce the number of experiments compared with traditional methods. Capacity factors were determined and the enthalpy and entropy of transfer from the mobile phase to the stationary phase, Delta H degrees and Delta S degrees, respectively, were calculated using the linear Van't Hoff equation (dependence of In k' on 1/T). A retention prediction system (RPS) for these compounds in GC was investigated. The molecular connectivity index was used to describe the quantitative structure relationships. Enthalpy - entropy compensation revealed that the mechanism was similar for all the compounds studied.