INEQUALITY OF TEMPERATURE INCREMENTS OF N-ALKANE HOMOLOGS AS ONE OF THE REASONS FOR THE NONLINEAR VARIATION OF SORPTION PARAMETERS OF SUBSTANCES IN TEMPERATURE-PROGRAMMED GAS-CHROMATOGRAPHY

GC behavior of C-6-C-17 n-alkanes has been investigated at different temperatures of isothermal analysis and under temperature programming conditions using two capillary columns coated with OV-101 and OV-351 stationary phases. Temperature increments have been calculated for the homologs and their inequality has been demonstrated for each member of the n-alkane series. It was shown that the nonlinear individual temperature variation of the energy of dispersive interaction of n-alkane homologs with the stationary phase, which was observed under isothermal conditions, may be one of the main reasons for the nonlinear change in sorption parameters of n-alkanes in temperature-programmed gas chromatography.