Isothermal retention indices on poly(3,3,3-trifluoropropylmethylsiloxane) stationary phases.

Isothermal retention indices (I) of 56 solutes of varied chemical nature and polarity were determined by a well-proven accurate method on poly(3,3,3-trifluoropropylmethylsiloxanes) with trifluoropropyl group percentages between 0 and 50% within the 353-413 K temperature range. The column temperature effect on the retention index for a representative set of solutes was studied. The linear model and the recent expression I = a + bT(-1) + c ln T were discussed. The retention index dependence on the polymer polarity was also investigated. Principal component analysis and multiple linear regression (MLR) were applied to obtain retention models relating the I values to physicochemical and molecular properties of the solutes chromatographed. The best model of prediction of the retention in these fluorinated stationary phases was obtained by using the Abraham's descriptors.