Calculation and Experimental Verification of Solute Retention in Liquid Chromatography Using Binary Eluents

Abstract

Abstract The chromatographic transport problem is a kinematic wave problem that generally leads to a set of coupled, nonlinear partial differential equations. In the linear elution mode of chromatography an approximation can be made which allows linearization of the set of equations and hence solution by the matrix eigenvalue decomposition method. To make the solution explicit, an expression for a multicomponent distribution isotherm is required. Generally, Langmuir isotherms are used for this purpose. In this work a recently published multicomponent isotherm, that can be derived from first principles, is applied to the problem. For the case of binary eluents the capacity factors and peak compositions of both system peaks and analyte peaks are calculated using the elution mode approximation and the isotherm referred to above. Experimental results pertain to the ion-exchange separation of alkali ions. A good agreement between calculated and measured quantities is observed. An important consequence of interactions among sample and eluent constituents for the practice of chromatography lies in the field of indirect detection. The possibility of universal detection in LC is briefly discussed.