Evaluation of theoretical models of non-electrolyte solutions in the prediction of Kóvats retention indices of branched alkanes in alkane stationary phases

CASTELLS, C. B.; CASTELLS, R. C.

JOURNAL OF CHROMATOGRAPHY - A

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 1996 vol. 755 p. 49 - 55

0021-9673

The models of Flory and of Elbro et al. were used for the prediction of Kováts retention indices of alkane solutes in squalane at three temperatures. The results were compared with experimental indices for sixty-two alkanes containing six to nine carbon atoms. Both models resulted in a better agreement with experimental indices than former prediction methods. A linear relationship was found between ( represent the experimental index, the calculated index and the molar volume of solute X, and VN is the molar volume of its isomeric normal alkane. The application of a correction formula based on this finding lowered the errors of the prediction to a half of its original value. Errors in the retention indices predicted by the model recently proposed by Kontogeorgis et al. [Fluid Phase Equilibria, 92 (1994) 35] were affected by temperature.