Influence of carrier gas on the prediction of gas chromatographic retention times based on thermodynamic parameters

McGinitie, Teague M.; Karolat, Bryan R.; Whale, Curtis; Harynuk, James J.

doi:10.1016/j.chroma.2010.09.068

Cited by 16 publications

(4 citation statements)

References 23 publications

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“…In all cases, thermodynamic parameters for the interaction of analytes with the stationary phase were calculated for both manually and autosampler‐injected experiments using the three‐parameter model based on the thermodynamic treatment of equilibrium constants developed by Clarke and Glew that we have previously used in retention time predictions .…”

Section: Resultsmentioning

confidence: 99%

Considerations for the automated collection of thermodynamic data in gas chromatography

McGinitie¹,

Harynuk

2012

J of Separation Science

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Thermodynamic modeling of retention times in gas chromatography depends on the accurate estimation of thermodynamic parameters. Previous research has used manual injections of samples with coinjection of a dead time marker to obtain accurate measurements of the retention factor of analytes. Ideally this process would be automated. Herein an approach is presented by which thermodynamic parameters can be estimated both autonomously and accurately. This method also allows for a consistent estimation of thermodynamic parameters regardless of factors such as data system delays and the nature of the void time marker employed. Ignoring these factors can lead to significant errors in the prediction of retention times when using thermodynamic models.

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Section: Resultsmentioning

confidence: 99%

Considerations for the automated collection of thermodynamic data in gas chromatography

McGinitie¹,

Harynuk

2012

J of Separation Science

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“…In many analytical procedures and catalytic reactions, the utilization of inert gases, such as nitrogen, helium, or argon, is unavoidable. Nitrogen is used in many applications, for example, purging gas in sampling methods, 1–3 carrier gas in diluting and gas generating systems, 4–9 in surface area measurements of porous materials, 10,11 as reactant in the Haber–Bosch process, 12 in cryogenic sampling applications, 13,14 and as carrier gas in gas chromatography (GC) 15–17 . Because in all of these applications the gas quality used is usually 5.0 (99.999% purity) or 6.0 (99.9999% purity), the remaining volatile organic compounds (VOCs) and water do not pose an interference to the different applications.…”

Section: Introductionmentioning

confidence: 99%

Determination of trace compounds and artifacts in nitrogen background measurements by proton transfer reaction time‐of‐flight mass spectrometry under dry and humid conditions

et al. 2021

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A qualitative analysis was applied for the determination of trace compounds at the parts per trillion in volume (ppt v ) level in the mass spectra of nitrogen of different qualities (5.0 and 6.0) under dry and humid conditions. This qualitative analysis enabled the classification and discovery of hundreds of new ions (e.g., [S x ]H + species) and artifacts such as parasitic ions and memory effects and their differentiation from real gas impurities. With this analysis, the humidity dependency of all kind of ions in the mass spectrum was determined. Apart from the inorganic artifacts previously discovered, many new organic ions were assigned as instrumental artifacts and new isobaric interferences could be elucidated. From 1140 peaks found in the mass range m/z 0-800, only 660 could be analyzed due to sufficient intensity, from which 463 corresponded to compounds. The number of peaks in nitrogen proton transfer reaction (PTR) spectra was similarly dominated by nonmetallic oxygenated organic compounds (23.5%) and hydrocarbons (24.1%) Regarding only gas impurities, hydrocarbons were the main compound class (50.2%). The highest contribution to the total ion signal for unfiltered nitrogen under dry and humid conditions was from nonmetallic oxygenated compounds. Under dry conditions, nitrogen-containing compounds exhibit the second highest contribution of 89% and 96% for nitrogen 5.0 and 6.0, respectively, whereas under humid conditions, hydrocarbons become the second dominant group with 69% and 86% for nitrogen 5.0 and 6.0, respectively. With the gathered information, a database can be built as a tool for the elucidation of instrumental and intrinsic gas matrix artifacts in PTR mass spectra and, especially in cases, where dilution with inert gases plays a significant role. K E Y W O R D Sgas impurities, gas traces, industrial gases, proton transfer reaction time-of-flight mass spectrometry, volatile organic compounds

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“…While publications focused on estimating/improving estimations of thermodynamic parameters and predicting retention times in GC and GC × GC appeared over the years , only a few specifically included peak width prediction. In the early 2000s, Lomsugarit and coworkers divided the adjusted peak width, w R ′, into hold‐up width, w M , and unadjusted peak width, w R .…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics‐based modelling of gas chromatography separations across column geometries and systems, including the prediction of peak widths

Stevenson

Harynuk

2019

J of Separation Science

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Thermodynamics-based models have been demonstrated to be useful for predicting retention time and peak widths in gas chromatography and two-dimensional gas chromatography separations. However, the collection of data to train the models can be time consuming, which lessens the practical utility of the method. In this contribution, a method for obtaining thermodynamic-based data to predict peak widths in temperature-programmed gas chromatography is presented. Experimental work to collect data for peak width prediction is identical to that required to collect data for retention time prediction using approaches that we have presented previously. Using this combined approach, chromatograms including retention times and peak widths are predicted with very high accuracy. Typical errors in retention time are < 0.5%, while errors in peak width are typically < 5% as demonstrated using polycycic aromatic hydrocarbons and a mixture containing compounds with aldehyde, ketone, alkene, alkane, alcohol, and ester functionalities. K E Y W O R D Speak width prediction, retention prediction, thermodynamic modeling As such, over the last few decades, researchers have developed methods and tools for predicting and simulating GC separations. Among the approaches to predictive modeling of GC separations, thermodynamic-based models have received a great deal of attention over the years. Much of

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Influence of carrier gas on the prediction of gas chromatographic retention times based on thermodynamic parameters

Cited by 16 publications

References 23 publications

Considerations for the automated collection of thermodynamic data in gas chromatography

Considerations for the automated collection of thermodynamic data in gas chromatography

Determination of trace compounds and artifacts in nitrogen background measurements by proton transfer reaction time‐of‐flight mass spectrometry under dry and humid conditions

Thermodynamics‐based modelling of gas chromatography separations across column geometries and systems, including the prediction of peak widths

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