solvent

in liquid-liquid distribution
https://doi.org/10.1351/goldbook.S05751
The term applied to the whole initial liquid phase containing the extractant.
Notes:
  1. The solvent may contain only one @E02299@ or it may be a @CT07545@ homogeneous mixture of @E02299@(s) with diluent(s) and also sometimes modifiers and accelerators.
  2. The term solvent must not be used as a synonym for any of the individual components of a @CT07545@ liquid phase even where, in the case of a single component (e.g. 3-methylbutan-2-one or tributyl phosphate), it becomes identical with the @E02299@.
  3. The term may be qualified to denote the extract from a given processing step e.g. loaded solvent.
Source:
PAC, 1993, 65, 2373. 'Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations 1993)' on page 2381 (https://doi.org/10.1351/pac199365112373)