Transient flow in response to a pressure pulse in gas chromatography.
The analysis of flow through a gas chromatography column has traditionally assumed the presence of steady-state conditions. However, when rapid changes in inlet pressure are introduced, a significant transient period is observed, leading to a failure of the steady-state model. Through the introduction of a one-dimensional continuity equation into the basic set of equations, a nonlinear partial differential equation is derived to describe the evolution of pressure profiles in a capillary gas chromatography column. A numerical solution is used to solve the differential equation for the case of a pulse injection under isothermal conditions, and comparisons with experimental holdup and retention times show very good agreement.
Nahir
Tal M
TM
Department of Chemistry, California State University, Chico, California 95929-0210, USA. tnahir@csuchico.edu