The term applied to the whole initial liquid phase containing the extractant
The solvent may contain only one extractant or it may be a composite homogeneous mixture of extractant(s) with diluent(s) and also sometimes modifiers and accelerators.
The term solvent must not be used as a synonym for any of the individual components
of a composite 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 extractant.
The term may be qualified to denote the extract from a given processing step e.g.
PAC, 1993, 65, 2373
(Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations
on page 2381
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook