ASYMMETRY OF PEAK SHAPES IN LINEAR GAS-LIQUID-CHROMATOGRAPHY

Abstract

A mathematical model describing axial dispersion, interparticle mass transfer, intraparticle gas diffusion, and diffusion in a uniform thickness liquid film is used systematically to investigate the influence of intraparticle diffusivity, diffusivity in a stationary liquid phase (SLP), partition coefficient, and thickness of liquid film on the shape of the peaks in linear gas-liquid chromatography by converting Laplace transformed equations into time domain. The low diffusivities of intraparticle and/or SLP can cause the asymmetry and long tail in chromatographic peaks. A higher partition coefficient and the film thickness at low diffusivities also give skewed peaks. At a higher mass transfer rate, the peak becomes sharper. From these results a guide can be suggested to avoid the asymmetric condition of long-tailing peaks.