https://doi.org/10.1351/goldbook.C01371
  1. (in an ion exchanger) The mobile exchangeable ions.
    Source:
    PAC, 1993, 65, 819. (Nomenclature for chromatography (IUPAC Recommendations 1993)) on page 854 [Terms] [Paper]
  2. (in colloid chemistry) Ions of low @[email protected], with a charge opposite to that of the @[email protected] ion.
    Source:
    PAC, 1972, 31, 577. (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 607 [Terms] [Paper]