2. Basic description of the prediction model for time retention
As described in reference. there are several equations which may be utilized to represent the influence of the retention factor with temperature. In this study Eqs. (1)-(3) were used as templates for the retention factor, seeing as its parameters (AH and AS) have thermodynamic meaning and allow correction of these with temperature by the introduction of the parameter ACp.
where R is the ideal gas constant and p is the ratio between the volume of the column phases.
Parameter AH, AS and ACP are associated with the solute's thermodynamic transition between the stationary and mobile phases. it is possible to check the consistency of the estimated parameters, especially when comparing different compounds, but from the same functional group.
Once the expressions for dead time and retention factor are defined, retention time can be determined by solving the well- known equation in GC, according to Eq
Where NExp is the number of temperature programs, and or top the retention time as predicted by the model in the case of the pth temperature program T (t) of the ith component.
For solving Eq, the classic procedure described in Ref was used, where the peak position over time (trajectory) is calculated at small time steps until reaching the end of the column.