Solvating gas-solid chromatography

Abstract

Capillary columns containing microparticulate adsorbents were used with CO2 as the mobile phase. By operating at selected temperatures, the CO2 mobile phase changed from liquid or supercritical fluid to gas between the column inlet and outlet. The column efficiency was examined for both situations. Similar minimum‐reduced plate heights (h∼1.5) were obtained for both situations, however, higher optimum mobile phase linear velocity (uopt) was observed when using a mobile phase that changed from supercritical fluid to gas than from liquid to gas. Silica and alumina adsorbents provided high selectivities for unsaturated (olefinic and aromatic) hydrocarbons. Silica adsorbents were more suitable than alumina for the separation of highly unsaturated compounds such as aromatic compounds, while alumina‐packed capillary columns yielded lower resistance to CO2 mobile phase flow and allowed faster separations. Chromatographic separations can be optimized by combining various modes of chromatography [i.e., liquid chromatography (LC), supercritical fluid chromatography (SFC), and gas chromatography (GC)] along the column length. ©1999 John Wiley & Sons, Inc. J Micro Sep 11: 359–365, 1999

High-Resolution Capillary Isoelectric Focusing of Complex Protein Mixtures from Lysates of Microorganisms

“…Linear polyacrylamide-coated capillary columns were prepared according to the procedure described by Hjerten and Zhu . For HPC- and PVA-coated fused-silica capillaries, the HPC powder was dissolved in room-temperature water and the PVA powder in boiling water to a final concentration of 5% (w/w). The polymer solutions were left overnight to eliminate bubbles.…”

Supercritical Fluid and Unified Chromatography

“…of increasing importance, particularly if ternary mobile phases increase in use. Shen and Lee evaluated solvating gas chromatography (SGC) for microcolumns (14). SGC is a technique performed using a compressible, solvating mobile-phase-like CO 2 with high inlet pressure on packed columns but with the column outlet at atmospheric pressure.…”

Narrow Bore Packed Column Designed for Capillary Gas Chromatograph

“…In these studies, particle sizes of lower than 10 µm were typically used. Based on these approaches the resolutions were clearly improved [25,26], although, at the same time, sample loading capacity was significantly decreased with a higher inlet pressure. Therefore, a specific instrument was necessary for the use of these packed-capillary columns in many cases.…”