Effects of stationary phase cross-linking and ion-exchange capacity on the retention of carboxylic acids in ion-exclusion chromatography using sulfonated resins

摘要

Ion-exclusion chromatography (IEC) has been widely used inudthe separation of carboxylic acids, finding applications in theudanalysis of food and beverages, pharmaceuticals, biologicaludsamples, and acid rain samples.' The retention mechanism ofudcarboxylic acids in ion-exclusion chromatography has also beenudinvestigated in many studies, and the factors which affectudretention can be divided into three categories: analyte effects,udmobile phase effects, and stationary phase effects.udIn IEC, the chromatographic system can be considered toudconsist of three phases: the mobile phase which comprises theudeluent passing through the interstitial volume of the column, theudstationary phase which comprises the occluded liquid trappedudwithin the pores of the resin and the resin phase which is theudsolid resin network and functionalized groups.' In this mode ofudchromatography, the analytes being separated have the sameudcharge as the functional group on the resin; that is, anions areudseparated on cation-exchange columns and cations are separatedudon anion-exchangec columns.