Investigation of the Determination of Diffusion Coefficients of Gases into Liquids from Reversed-Flow Gas Chromatography

• Published in: Instrumentation science & technology Vol. 34; no. 4; pp. 435 - 454
• Main Authors: Gavril, Dimitrios, Gabriel, Aristea
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.08.2006
• Subjects: Diffusion coefficient; Gas chromatography; Mass transfer coefficient; Vapour-liquid equilibria; Vinylchloride; Water
• ISSN: 1073-9149; 1525-6030
• DOI: 10.1080/10739140600648852

The interaction of vinyl chloride (VC) with water is used as the model system for the investigation of the determination of diffusion coefficients of gases into liquids from revered-flow gas chromatography (RF-GC). A thorough, full investigation of the initially suggested methodologies of RF-GC [Anal. Chem. 1989, 61, 2231-2237 and Adv. Chromatogr. 2000, 40, 231-273] is carried out. The appropriate experimental conditions for the measurement of accurate liquid diffusivities (e.g., quiescent or stirred liquids) are investigated, and an insight into the physical meaning of the measured physicochemical parameters is attempted. In order for liquid diffusion to be the main broadening factor, it is necessary to ensure the regularity of the liquid stationary phase, which can be achieved by stirring the liquid substance under study. Furthermore, the experimentally obtained diffusion coefficients, the respective mass transfer coefficients, as well as the activation energy for the diffusion of VC in water are of the same order of magnitude and are very close to the values obtained by other techniques or calculated from empirical equations, ascertaining the potential of the presented methodology.