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.
Source:
Orange Book, p. 90
PAC, 1993, 65, 2373 (Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations 1993)) on page 2385