Ion-Exclusion Chromatography HPICE

The introduction of ion-exclusion chromatography is attributed to Wheaton and Bauman [1], It serves, above all, for the separation of weak inorganic and organic acids. In addition, ion-exclusion chromatography can be utilized for the separation of alcohols, aldehydes, amino acids, and carbohydrates. Due to Donnan exclusion, fully dissociated acids are not retained at the stationary phase, eluting therefore within the void volume as a single peak. Undissociated compounds, however, can diffuse into the pores of the resin, since they are not subject to Donnan exclusion. In this case, separations are based on non-ionic interactions between the solute and the stationary phase. 

In combination with ion-exchange chromatography (HPICE/HPIC coupling), a wealth of inorganic and organic anions can be separated within 30 minutes in a single run. 

Detection is usually carried out by measuring the electrical conductivity. When combined with a suppressor system, this detection method is superior to all other detection methods such as, for example, refractive index or UV detection at low wavelengths with regard to specificity and sensitivity. 

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