title: Simple equations to simulate closed-loop recycling liquid-liquid chromatography: Ideal and non-ideal recycling models.
abstract: The ideal (the column outlet is directly connected to the column inlet) and non-ideal (includes the effects of extra-column dispersion) recycling equilibrium-cell models are used to simulate closed-loop recycling counter-current chromatography (CLR CCC). Simple chromatogram equations for the individual cycles and equations describing the transport and broadening of single peaks and complex chromatograms inside the recycling closed-loop column for ideal and non-ideal recycling models are presented. The extra-column dispersion is included in the theoretical analysis, by replacing the recycling system (connecting lines, pump and valving) by a cascade of Nec perfectly mixed cells. To evaluate extra-column contribution to band broadening, two limiting regimes of recycling are analyzed: plug-flow, Nec→∞, and maximum extra-column dispersion, Nec=1. Comparative analysis of ideal and non-ideal models has shown that when the volume of the recycling system is less than one percent of the column volume, the influence of the extra-column processes on the CLR CCC separation may be neglected.
authors.affiliation: Kurnakov Institute of General & Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 31, Moscow 119991, Russia. Electronic address: kost@igic.ras.ru.
authors.forename: Artak E
authors.initials: AE
authors.lastname: Kostanyan
mesh_terms: D000465:Algorithms; D002853:Chromatography, Liquid; D008962:Models, Theoretical
keywords: Closed-loop recycling counter-current chromatography; Ideal and non-ideal recycling equilibrium cell models; Peak and chromatogram equations; Resolution