extractant

Synonym: extracting agent
https://doi.org/10.1351/goldbook.E02299
The active component(s) primarily responsible for transfer of a solute from one phase to the other.
Notes:
  1. The term extracting agent is a synonym but solvent and ligand should not be used in this context.
  2. Certain extractants that consist of liquids immiscible with water (e.g. tributyl phosphate or certain @K03386@) might comprise the only component of the initial organic phase but extractant(s) can also be dissolved in diluent.
Sources:
Orange Book, 2nd ed., p. 91 (https://media.iupac.org/publications/analytical_compendium/)
PAC, 1993, 65, 2373. 'Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations 1993)' on page 2380 (https://doi.org/10.1351/pac199365112373)