Development and validation of retention models in supercritical fluid chromatography for impregnation process design

The retention factor is the key quantity for the thermodynamic analysis of the retention mechanism in chromatographic experiments. In this work, we measure retention factors for moderately polar solutes on four silica-based porous matrices as stationary phases by supercritical fluid chromatography. Elution of the solutes is only possible with binary mixtures of supercritical carbon dioxide (sc-CO₂) and modifier (methanol) due to the low polarity of pure sc-CO₂. The addition of modifiers makes the retention mechanism more complex and masks interactions between solute and stationary phase. In this work, we develop and validate several retention models that allow the obtaining of retention factors in modifier-free sc-CO₂. Such models pave the way for quantifying adsorption interactions between polar solutes and non-swellable porous matrices in pure sc-CO₂ based on retention data obtained in sc-CO₂-modifier mixtures. The obtained information will thereby facilitate the understanding and design of impregnation processes, which are often performed in modifier-free conditions.

Subjects

aerogels

adsorption

impregnation

supercritical fluid chromatography

retention model

DDC Class

540: Chemie

Funding(s)

Publikationsfonds 2021

More Funding Information

Publishing fees supported by Funding Programme Open Access Publishing of Hamburg University of Technology (TUHH).

Publication version

publishedVersion

Lizenz

https://creativecommons.org/licenses/by/4.0/

Name

applsci-11-07106-v2.pdf

Size

2.45 MB

Format

Adobe PDF

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Development and validation of retention models in supercritical fluid chromatography for impregnation process design