Theory of the propagation of finite concentration bands in gas chromatography. A numerical solution of the ideal problem

Abstract

The solution of the set of partial differential equations that determines the shape of the elution profile of a finite concentration band in gas chromatography is discussed. It is shown that for the simple case of the elution of a one-component band, in the approximation of the nonlinear, ideal problem, the use of a Godounov scheme permits the design of a computer program which gives an excellent approximation of the elution band profile. In the case of a strong isothermal effect, with «-hexane adsorbed on graphitized thermal carbon black, the comparison between the calculated results and those obtained experimentally shows excellent agreement. At present the most significant source of discrepancy between experimental and predicted profiles is the experimental errors made in the determination of the equilibrium isotherm of the studied compound between mobile and stationary phase, and especially in the determination of the curvature of this isotherm at the origin.

Effect of the ionic strength of salts on retention and overloading behavior of ionizable compounds in reversed-phase liquid chromatography

“…The ED model was solved using the Rouchon program based on the finite difference method [12,[27][28][29].…”

Influence of particle size and shell thickness of core–shell packing materials on optimum experimental conditions in preparative chromatography

“…(5)] was carried out by Rouchon method [17,18]. The time and space increments ( t, z) were chosen in order to accurately simulate the band dispersion for the two components by the numerical error of calculation [1]:…”

Effect of the pH, the concentration and the nature of the buffer on the adsorption mechanism of an ionic compound in reversed-phase liquid chromatography

“…The boundary conditions used are the classical Danckwerts-type boundary conditions [35,38] at the inlet and outlet of the column. The ED model was numerically solved using the Rouchon program based on the finite difference method [35,[39][40][41].…”