A quantitative structure-retention relationship (QSRR) model has been developed for the gas chromatographic Kováts indices of 89 saturated esters on ten different polar stationary phases by multiple linear regression analysis (MLR). The ten stationary phases are: SE-30, OV-7, DC-710, OV-25, 100% phenyl, DC-230, DC-530, XE-60, OV-225 and Silar-5CP [1-2]. In the present study, geometrical optimization and electrostatic potential calculations have been performed for all saturated esters at the B3LYP/6-31G* level of theory [3]. A number of statistically-based parameters derived from molecular surface electrostatic potential and average local ionization energy obtained. Linear relationships between gas-chromatographic relative Kováts retention index (RRI) esters and these statistical parameters have been established by multiple regression method. Results show statistical parameters derived from molecular surface electrostatic potential and average local ionization energy can use to predict RRI of esters because interaction forces between solute and stationary and mobile phase are non-covalent in nature. The accuracy of all the developed models were cross-validation using leave-one-out (LOO), Y-randomization and external validation through an odd-even number and division of the entire dataset into training and test sets [4].
