Mechanistic interpretations and simulations of induced peaks in liquid chromatography

Abstract

A general model that does not depend upon a specific retention mechanism Is proposed to explain the appearance of anomalous peaks in liquid chromatography. The model Is then applied to reversed-phase ion-interaction (ion-pair) chromatography to account for Induced peaks observed In real systems.

System peaks observed in capillary liquid chromatography with eluents containing triethylamine

“…In all these cases, the retention time of the system peak is determined by the TEA affinity to the stationary phase as with any other analyte. This interpretation of the experimental observations is in agreement with the conclusions published earlier [2,3,12].…”

“…Therefore, the first system peak would correspond to the injection peak [4] indicating the dead time. The second system peak, positive for water and acetonitrile samples and negative for the methanol sample was considered to be a local excess and deficiency, respectively, of TEA on the stationary phase [2]. The second peak would thus represent the retention time of TEA in the given chromatographic system.…”

Characterization of warfarin unusual peak profiles on oligoproline chiral high performance liquid chromatography columns

“…This result in desorption of some additive molecule migrating along the column to generate system peak. System peak also termed as pseudo peak, ghost peak, eigenpeak, vacancy peak, induced peak, dip peak, or perturbation peak has been studied since 1970s [34][35][36][37][38][39][40][41][42][43][44]. Levin and Grushka realized the system peaks were produced in relaxation process to a new state of equilibrium [41].…”

Ion-Pair High-Performance Liquid Chromatographic Retention Behavior of Copper(II)–1-Oxa-4,7,10,13- tetraazacyclopentadecane Complex

“…The detection reagent is a UV-visible absorbing compound. Why the system peaks appear as (Ϫ) and (ϩ) peaks is simply explained as follows: MeCN and water are already components in the mobile phase; the absorbance decreases (Ϫ peak) by dilution with their addition as a sample solution because they are UV-visible nonabsorbing compounds and increases (ϩ peak) by a dissolving effect with removal of the detection reagent adsorbed on the stationary phase (17,18). These peaks are a disadvantage in determination of the sample because they sometimes interfere with sample peaks.…”