Abstract :
[en] In light of the wide applicability of multidimensional GC techniques in the analysis of complex samples, method development and optimization have become more challenging and time-consuming (1). Therefore, a renewed interest in modeling GC separations has sprung. In fact, establishing accurate modeling procedures helps bypass demanding trial and error optimizations, thus significantly decreasing the number of runs preceding the actual chromatographic separation. Typically, the GC×GC run is modeled as a whole complex set. However, in this research, the comprehensive two-dimensional gas chromatography (GC×GC) separation is modeled as
individual subsystems in which the primary and secondary columns are treated separately and the cryogenic modulator is considered as a consecutively second injection device. In this scheme, retention times are modeled using two predictive approaches. The first uses the general temperature-programmed retention time (2,3) and the second is based on thermodynamic modeling(4). Both approaches use retention data retrieved from isothermal runs and simulate the temperature-programmed GC runs as series of infinitesimal isothermal time intervals
during which both the retention factor and the carrier gas velocity are considered constant. The performance of both approaches is evaluated using several standards and experimental conditions (two modes of gas flow regulation and different temperature programs). While the modeling error is considerably smaller for the thermodynamic model, predictions with both approaches are in good agreement with the experimental data. Additionally, both models provide accurate retention time predictions for different chromatographic conditions.
References
1. Prebihalo, S. E.; Berrier, K. L.; Freye, C. E.; Bahaghighat, H. D.; Moore, N. R.; Pinkerton, D. K.; Synovec, R. E.
Anal. Chem. 2018, 90, 505–532.
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3. Calvin Giddings, J. J. Chromatogr. A 1960, 4, 11–20.
4. Karolat, B.; Harynuk, J. J. Chromatogr. A 2010, 1217, 4862–4867.
