Chromatographic framework for analysing lithium perchlorate salt dependence on solute binding mechanisms to porous graphitic carbon surfaces

Abstract

KeyWordsColumn liquid chromatography Porous graphitic carbon Salute bTndTng mechanism LithTum perchlorate Summary A general model to describe the lithium perchlorate salt effect on both phenol derTvatTve-porous graphitic carbon (PGC) association and the selectivity process is presented. Thermody namic functions of solute transfer from mobile phase to PGC surface were determined. Varia tion plots of solute transfer data versus lithium perchlorate concentration (x) in the bulk solvent indicated a change in both the solute PGC assodation and selectivity mechanisms. Enthalpy entropy compensation reveals that this assodation process is independent of the molecular structure of phenol. This study shows the Tmportance of taking into account, (a) salvation by lithium perchlorate in the bulksolvent and (b) possible perchlorate-anTon adsorption on porous graphTtic carbon Tn order to determine optTmum conditTons forseparation of phenol deriva-tTves Tn this system.

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