Simulation of spatial thermal gradient gas chromatography.

Autor: Leppert J; Institute of Agricultural Engineering, University of Bonn, Nussallee 5, D-53115 Bonn, Germany. Electronic address: jleppert@uni-bonn.de., Müller PJ; Institute of Agricultural Engineering, University of Bonn, Nussallee 5, D-53115 Bonn, Germany., Chopra MD; Advachrom, P.O. Box 1243, Wilmington, DE 19801, USA., Blumberg LM; Advachrom, P.O. Box 1243, Wilmington, DE 19801, USA., Boeker P; Institute of Agricultural Engineering, University of Bonn, Nussallee 5, D-53115 Bonn, Germany; HyperChrom SA, 21 Avenue Monterey, L-2163 Luxembourg, Luxembourg.
Jazyk: angličtina
Zdroj: Journal of chromatography. A [J Chromatogr A] 2020 Jun 07; Vol. 1620, pp. 460985. Date of Electronic Publication: 2020 Mar 01.
DOI: 10.1016/j.chroma.2020.460985
Abstrakt: A model to simulate the gas chromatographic separation in the presence of a spatial thermal gradient is presented. This model is developed from existing models for the prediction of retention times in temperature programmed GC. It is based on basic fluid mechanics of gasses in capillaries to describe the properties of the mobile phase and a thermodynamic model to describe retention of solutes in a stationary phase. This model is expanded to incorporate a spatial thermal gradient. The development of the peak width during the chromatographic separation is modeled by a differential equation, which uses the solute residency, the inverse of the solute velocity, instead of the solute velocity. The presented model is compared to measurements of n-alkanes with conventional temperature programmed GC-FID and to measurements with a hyper-fast flow-field thermal gradient GC (FF-TG-GC) coupled with a MS. The FF-TG-GC enables the use of a spatial thermal gradients. For temperature programmed GC-FID, without spatial thermal gradients, calculated retention times are mostly within 1% of measured values. For the FF-TG-GC-MS with a thermal gradient the simulation showed a deviation of the spatial thermal gradient from a linear to a nonlinear gradient, which could be confirmed by measuring the shape of the spatial gradient. The calculated retention times for the nonlinear gradient are also mostly within 1% of measured values. Calculated peak widths are smaller than measured peak widths by 10 to 15% in the case of the conventional GC-FID and by 30 to 50% for the FF-TG-GC-MS. The relation between the measured and calculated variances shows a linear correlation which can be used to correct the calculated variance and peak width. With this correction the difference for the peak widths is reduced to 4-10% for the conventional GC and below 10% for the majority of solutes with exceptions for early and late eluted n-alkanes (up to 25% difference).
Competing Interests: Declaration of Competing Interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: