Behavior of n-alkanes on poly(oxyethylene) capillary columns: Evaluation of interfacial effects

The solvation behavior of n-alkanes on poly(oxyethylene) was studied employing capillary gas chromatography. Interfacial effects were discriminated and evaluated through the analysis of retention data from six commercial fused-silica capillary columns, having film thicknesses of 0.15–5 μm. Expressions for the mixed retention mechanism in capillary columns were deduced from assumptions of a general character. Partition coefficients were determined for the n-alkanes up to 28 carbon atoms, at temperatures ranging from 40 to 240°C. In agreement with other authors, it was observed that interfacial phenomena contribute poorly to the chromatographic retention, being negligible over 140°C for homologues with less than 16 carbons.