Ion exclusion chromatography

Abstract

Ion exclusion chromatography (IEe) is a relatively old separation technique, attributed to Wheaton and Bauman, which is now staging an impressive comeback for the simultaneous determination of ionic species. IEC provides a useful technique for the separation of ionic and nonionic substances using an ion exchange stationary phase in which ionic substances are rejected by the resin while nonionic or partially ionized substances are retained and separated by partition between the liquid inside the resin particles and the liquid outside the particles. The ionic substances therefore pass quickly through the column, but nonionic (molecular) or partially ionized substances are held up and are eluted more slowly. IEC is also referred to by several other names, including ion exclusion partition chromatography, ion chromatography-exclusion mode, and Donnan exclusion chromatography. In this article we use the term ion exclusion chromatography.