Peak distortion effects of suramin due to large system peaks in bioanalysis using ion-pair adsorption chromatography

Sample injections in ion-pair adsorption chromatography lead to changes in the established equilibria of the eluent components at the top of the column, which in turn lead to migrating concentration changes in the column (system peaks). Large system peaks contain big concentration deviations of the mobile phase components compared with the bulk composition in the eluent. Analyte peaks are distorted upon combined elution with large system peaks. In bioanalysis, samples that deviate considerably from the eluent are often injected, resulting in large system peaks. An illustrative example of such analyte peak distortions in bioanalysis is given for the case of suramin, and guidelines are given for avoiding the effects.