Counter-ions

{
  "id": "MLC-T-CHM-002639",
  "term": "Counter-ions",
  "field": "Chemistry",
  "definition": "Ions of opposite charge that associate with a charged species, such as a macromolecule or an ion-exchange resin, to maintain electroneutrality. In ion-exchange chromatography, counter-ions are reversibly exchanged with ions from the sample solution. Their presence influences the electrostatic interactions and solubility of charged molecules in solution.",
  "subject": "Analytical Chemistry",
  "see_also": [
    "colloidal",
    "relative molecular mass"
  ],
  "references": [
    "PAC, 1993, 65, 819. 'Nomenclature for chromatography (IUPAC Recommendations 1993)' on page 854 (https://doi.org/10.1351/pac199365040819)",
    "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 (https://doi.org/10.1351/pac197231040577)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/counter-ions/"
}