Characterization of Carbon Dioxide Mobile Phase Density Profiles in Packed Capillary Columns by Raman Microscopy

Autor:	Andrew W. Orton, L. Robert Baker, Brent A. Horn, Steven R. Goates
Rok vydání:	2009
Předmět:	Density gradient Chemistry Capillary action Analytical chemistry Compressible flow symbols.namesake Phase (matter) Supercritical fluid chromatography Compressibility symbols Gas chromatography Raman spectroscopy Instrumentation Spectroscopy
Zdroj:	Applied Spectroscopy. 63:108-111
ISSN:	1943-3530 0003-7028
DOI:	10.1366/000370209787169803
Popis:	Efforts to understand and optimize separations employing compressible mobile phases have been limited by a lack of understanding of the mobile phase density gradient. Mobile phase compressibility leads to gradients in linear velocity and solute retention and affects separation speed and efficiency, especially in packed columns. Gas chromatography (GC), supercritical fluid chromatography (SFC), and solvating gas chromatography (SGC) each rely on compressible mobile phases. This work describes the on-column density measurement of carbon dioxide, a common carrier fluid for SFC and SGC, in packed capillary columns using Raman microspectroscopy of the position of the Fermi doublet. Correlation of the spectrum with density was calibrated over a pressure range of 15 to 290 atm at 125 and 150 °C, which then allowed for determination of the density gradient of fluid flowing through a packed capillary column. The results of this work will be used to model the flow behavior of compressible fluids to understand the effects of mobile phase compressibility on separation speed and efficiency.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ecb94b2646933a7a89277a88a5b44692 https://doi.org/10.1366/000370209787169803 Zobrazit plný text záznamu