Article
Temperature Programmed GC: Why Are All Those Peaks So Sharp?
LCGC North America
(2019)
Abstract
Temperature programming is used for most separations in capillary gas chromatography (GC) today. Despite this, many of the principles by which we understand temperature-programmed capillary column separations are based on ideas developed using packed columns and isothermal conditions. This installment of "GC Connections" dives into temperature programming. First, the differences in peak widths and retention times between temperature programmed and isothermal chromatograms are examined. Why are all the peaks so sharp in temperature programmed GC, yet they get broader (and shorter) in isothermal GC? Next, we explore some early ideas about temperature programming and peak broadening that explain why the peaks are so sharp in temperature-programmed GC, and why the peak spacing is different from isothermal GC. Finally, we examine an important consequence of our ability to program temperature: the need for temperature programming in splitless and other injections that use "solvent effects" and other peak focusing mechanisms. These points are illustrated using several historical figures and chromatograms from the early days of GC.
Disciplines
Publication Date
July 1, 2019
Citation Information
Nicholas Snow. "Temperature Programmed GC: Why Are All Those Peaks So Sharp?" LCGC North America Vol. 37 Iss. 7 (2019) p. 450 - 456 ISSN: 1939-1889 Available at: http://works.bepress.com/nicholas_snow/53/