ultimate capacity

in solvent extraction
Synonym: stoichiometric capacity
https://doi.org/10.1351/goldbook.U06546
The theoretical maximum capacity of a solvent containing a given concentration of extractant for a solute under any conditions. Where appropriate the term stoichiometric capacity can be used.
Source:
PAC, 1993, 65, 2373. 'Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations 1993)' on page 2386 (https://doi.org/10.1351/pac199365112373)