Composition profiles in multicomponent perturbation gas chromatography

Abstract

Recent work has extended perturbation gas chromatography theory to multicomponent systems and has demonstrated the procedure for determining multicomponent equilibrium isotherms from response peak retention times. For accurate use of the technique for equilibrium and rate measurement and for processes involving membrane and zeolite separations, an understanding of the response curves is helpful. This paper presents a tractable model for calculating multicomponent perturbation gas chromatography elution curves which incorporates both phase equilibrium and interphase mass-transfer rates. Example calculated curves agree well with experimental data and provide insight into peak shapes and their development. Eigenpulse injections can be used to simplify responses experimentally, enabling accurate retention times (for measuring equilibrium) and peak dispersion rates (for evaluating mass-transfer effects) to be obtained.Gas perturbation chromatography is an effective means of obtaining vapor-liquid and vapor-solid interphase transport properties. The response of a column which is

Immobilization of arginase and its application in an enzymatic chromatographic column: Thermodynamic studies of nor-NOHA/arginase binding and role of the reactive histidine residue

“…In order to confirm the binding properties of the immobilized enzyme on the chromatographic support, the study of the NOHA (N -hydroxy-l-arginine, an other well-known arginase inhibitor which is known to bind on the same active site than nor-NOHA) displacement of its arginase binding site by nor-NOHA was investigated using the Langmuir approach [47][48][49][50][51]. For this, single and multi-component isotherms were determined using the perturbation technique [47].…”

“…For this, single and multi-component isotherms were determined using the perturbation technique [47]. This method was described previously for the analysis of the progesterone displacement of its human binding site by ␤-estradiol [52].…”

Multicomponent Inverse Gas Chromatography: Determination of Solubility and Diffusivity in Ternary Polymer−Solvent Systems

“…Contrary to previous models, 5 the perturbation introduced in the system does not have to be calculated theoretically. Because the experimental technique allows the tracking of individual components, the amount of each solvent introduced, denoted by C 0i in eq 8, is calculated by integrating the elution curves.…”

“…Because the number of unknowns (four derivatives) was greater than the number of equations (two), an estimation procedure was used that combines the experimental results and available solution theories. A later modification of the model by Debarro et al 5 added the interphase mass-transfer rates to evaluate its effect on the peak's shape.…”

“…While Glover's model has been proven useful to estimate sorption isotherms for various ternary systems, its modification by Debarro et al 5 is not applicable in this case for the determination of diffusion coefficients. Only retention times from the peaks maximum were used for calculating the isotherms.…”