Relation between characteristic temperature and elution temperature in temperature programmed gas chromatography – Part II: Influence of column properties

• Published in: Journal of Chromatography A 2024-08, Vol.1728, p.464997, Article 464997
• Main Authors: Brehmer, Tillman, Boeker, Peter, Wüst, Matthias, Leppert, Jan
• Format: Article
• Language: English
• Subjects: Characteristic temperature; Computer simulation; Elution temperature; Method development in gas chromatography; Retention time prediction
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2024.464997

•Estimation of retention parameters by temperature programmed measurements.•Multivariate relationship of characteristic temperature and elution temperature.•Investigation of the stationary phase using a simulation of gas chromatography.•Investigation of the influence of the phase ratio using simulation and measurements.•Expansion of the prediction range compared to earlier approaches. The method development process in gas chromatography can be accelerated by suitable computer simulation tools using knowledge about the solute-column interactions described by thermodynamic retention parameters. Since retention parameters usually are determined under isothermal conditions, the presented work offers a step to estimate one of the most important retention parameters, the characteristic temperature Tchar by less laborious temperature programmed measurements. In the first part an empirical multivariate model was introduced describing the correlation between the elution temperature Telu of a solute and its characteristic temperature Tchar. Now in the second part a simulation model of GC and available retention data from a retention database was used to investigate the correlation between Telu and Tchar for an expanded range of heating rates and initial temperatures. In addition to part I, the simulation is used to investigate the influences of different properties of the separation column such as different phase ratios and column geometries like length and diameter or various stationary phases including SLB-5 ms, SPB-50, Stabilwax, Rtx-Dioxin2, Rxi-17Sil MS, Rxi-5Sil MS, ZB-PAH-CT, DB-5 ms, Rxi-5 ms, Rtx5 and FS5ms. The fit model is valid for all investigated stationary phases. The influence of the phase ratio to the correlation could be determined. Therefore, the model was expanded to this parameter. The expanded range of heating rates and the normalization for the system independent dimensionless heating rate required a further modification of the previously presented correlation model. The model now fits also under isothermal conditions. The results were used for estimation of the Tchar of an analyte from the elution temperature in the temperature program. The prediction performance was investigated and evaluated for 20 different temperature program conditions and at two phase ratios (β=125 and β=250). Under best conditions the estimated and the measured Tchar values show relative differences