Prediction of retention times of polycyclic aromatic hydrocarbons and n-alkanes in temperature-programmed gas chromatography

Abstract

We have developed an iterative procedure for predicting the retention times of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes during separations by temperature-programmed gas chromatography. The procedure is based on estimates of two thermodynamic properties for each analyte (the differences in enthalpy and entropy associated with movements between the stationary and mobile phases) derived from data acquired experimentally in separations under isothermal conditions at temperatures spanning the range covered by the temperature programs in ten-degree increments. The columns used for this purpose were capillary columns containing polydimethylsiloxane-based stationary phases with three degrees of phenyl substitution (0%, 5%, and 50%). Predicted values were mostly within 1% of experimentally determined values, implying that the method is stable and precise.

Rapid Temperature-Programmed Separation and Retention Prediction on a Novel Packed-Capillary Column in Gas Chromatography

“…Downsizing of the packed column also permits the use of the resulting miniaturized packed column in a modern capillary GC system without any special modification to the instruments, although the compatibility of the packed column to the temperature-programmed operation should be considered as typically reported in several publications dealing with the theoretical prediction of the retention time for separation with temperature programming. [13][14][15][16][17][18][19][20][21] In contrast to a number of papers for a theoretical prediction of the retention in GC, a comprehensive comparison of the compatibility of packed columns having different internal diameters to a rapid temperature program in a modern GC system had been quite limited. [21][22][23] In this work, novel packed-capillary columns were developed with a thin-wall capillary of stainless-steel, and the compatibility to a fast temperature-programmed separation was studied on the basis of a theoretical prediction of the retention by a numerical-integration method.…”

A simple, fast, and accurate thermodynamic‐based approach for transfer and prediction of gas chromatography retention times between columns and instruments Part I: Estimation of reference column geometry and thermodynamic parameters

“…In addition, thermodynamic methods are much more amenable to modeling comprehensive 2-D GC (GC × GC) separations when compared to the isovolatility curve generation methods that are required for use of the retention index in the second dimension of a GC × GC separation [7,19]. In the literature, a number of studies to predict retention time using thermodynamic-based models have been reported [1,5,7,[10][11][12][20][21][22][23][24][25]. However, there is room for improvement, especially with regard to translation of retention time predictions across columns (of the same stationary phase chemistry) with varying geometries, and translation between different instruments.…”

Phenomenon of dual- and single-retention behaviors of solutes and its validation by computational simulation in linear programmed temperature gas chromatography

“…Computer simulations are fast and practical but the underlying processes are not intuitively informative . Many methods using thermodynamic data to predict the PTGC retention times in different conditions have been published. However, the true retention behavior of solutes and chromatographic meaning of the thermodynamic parameters are not intuitively informative .…”