Abstract
In this paper, the efficiencies and peak capacities of columns packed with nonporous and porous particles were investigated under typical solvating gas chromatography (SGC) conditions using a carbon dioxide mobile phase. The contributions of mass-transfer resistance (Cstag) to the plate height from the stagnant mobile phase were compared for liquid chromatography (LC), supercritical fluid chromatography (SFC), and SGC using 5-μm nonporous and porous particles. The results show that the contribution of the Cstag term to the total mobile-phase mass-transfer resistance for porous particles decreased markedly from LC to SFC to SGC. In SGC, mass-transfer resistance in the stationary phase and longitudinal diffusion are more significant. The total mass-transfer terms for nonporous silica (5 and 10 μm) encapsulated with SE-54 (e.g., 1% w/w loading) were 30−40% higher than those for porous silica (5 μm, 120 Å, and 10 μm, 80 Å) encapsulated with SE-54 (e.g., 10% w/w loading). Polymer-encapsulated porous particles are more suitable for fast SGC than nonporous particles at the same linear velocity although higher column inlet pressure is required. Peak capacities of columns packed with nonporous particles were lower compared to columns packed with porous particles when the same linear velocity was used. High-speed separations can be achieved using very short columns packed with small porous particles in SGC.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.