FACTOR-ANALYSIS IN ION CHROMATOGRAPHY OF CARBOXYLATE IONS

The retention times of five carboxylate ions (formate, acetate, propio nate, n-butanoate and n-pentanoate) in ion chromatography were determi ned using 25 eluents prepared from NaHCO3 and Na2CO3. Principal compon ent analysis (PCA) and correspondence factor analysis (CFA) were appli ed to describe the behaviour of the carboxylate anions and the influen ce of the carbonate concentration of the eluents. With PCA, only one f actor is necessary to model the retention times of each ion studied. C FA offers an analysis of second-order effects and shows how the select ivities of the chromatographic systems are modified with either the ca rbonate concentration or the concentration ratio of NaHCO3 and Na2CO3.