Carbon dioxide versus xenon as a mobile phase for flow cell packed column SFC/FT‐IR

Abstract

Xenon is compared to carbon dioxide as a mobile phase for super critical fluid chromatography/Fourier transform infrared spectrometry. The study showed xenon to be comparable to carbon dioxide in terms of resulting chromatography for non‐polar analytes. Xenon was confirmed to be a very poor mobile phase, however, for polar analytes. It was determined that small wavenumber shifts in the infrared spectra of probe analytes occurred as either the density or temperature of the mobile phase was increased. The degree of these shifts was often similar for xenon and carbon dioxide. Analyte spectra for five different compounds were produced in both super critical xenon and carbon dioxide and compared to condensed phase and vapor phase library spectra. In all cases, carbon dioxide spectra were readily matched to their corresponding vapor phase spectra, despite having blanked portions of the spectrum due to carbon dioxide infrared absorption. Xenon produced technically superior spectra without such blanked regions, but at a much higher economical cost than carbon dioxide and with no real improvement in terms of library matching.

Supercritical Fluid Chromatography and Extraction

“…Gram-Schmidt reconstruction and spectral subtraction were used to enhance detection despite spectral background changes due to density programming (116). Kirschner and Taylor compared Xe to CO 2 mobile phases in packed-column SFC/flow cell FT-IR (117). Despite xenon's ability to transmit the full IR spectrum, both mobile phases produced equivalent spectral and librarysearching results with standards.…”

Confirmation of Crystal Structure of Poly(vinylidene fluoride) through the Detailed Structure Analysis of Vinylidene Fluoride Oligomers Separated by Supercritical Fluid Chromatography

“…We needed to separate them to each component by any method in order to prepare the single crystals and to obtain the detailed information on the crystal structure through the X-ray analysis. As for the separation of a mixture into components, the various types of methods have been reported, among which a supercritical fluid chromatography (SFC) is now becoming a quite useful method. − In many cases carbon dioxide is used as a development fluid for chromatography. When the temperature and pressure of carbon dioxide gas are increased above the critical temperature (31.3 °C) and critical pressure (72.9 atm), the gas changes into the so-called supercritical fluid state.…”

Capillary Supercritical Fluid Chromatography/Mass Spectrometry of Phenolic Mannich Bases with Dimethyl Ether Modified Ethane as the Mobile Phase

“…Xenon (>99.99%) was obtained from SL Gas, Lenzburg, Switzerland. Xenon was transferred from the gas reservoir into the pump as described in the literature …”