Theoretical study of the elution profile of a high-concentration sample anion in non-suppressed ion chromatography

In non-suppressed ion chromatography, an injection of a high concentration analyte on an anion-exchange column results in the leading and broadening of the peaks. The mechanism was elucidated by analyses of the behavior of various components on the elution model. When the analyte concentration was high, a large amount of eluent was expelled from the stationary phase. Subsequently the eluent concentration in the analyte band decreased, This resulted in a distortion of the analyte peak shape. The use of a large buffer capacity of the mobile phase to avoid the distortion is discussed. The distortion practically disappeared when a mobile phase was buffered with a high concentration glycine. (C) 1997 Elsevier Science B.V.