recovery factor [obsolete]

in an extraction process
The fraction or percentage (R%) of the total quantity of a substance extracted (usually into the organic solvent phase) under specified conditions. Specifically, R A = Q A Q A ', where Q A ' and Q A are the original and final quantities of the substance A. This term is not recommended. Fraction extracted should be used.
Orange Book, p. 90
PAC, 1993, 65, 2373 (Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations 1993)) on page 2385