The solvent extraction of an ionic compound from an aqueous into organic media can be described by the following equations

Q⁺(aq) + X^-(aq) < ====== > [Q⁺X^-]org

E_QX = [Q⁺X^-]_org/([Q⁺]_aq * [X^-]_aq)

In a solvent system water/chloroform, the following extraction constants have been observed:

Anions(as NBu₄⁺-salts)

General trend for anions:

MnO₄^- > ClO₄^- > SCN^- > I^- > NO₃^- > Br^- > HSO₄^- > OH^- > SO₄^2- > PO₄^3-


Quartenary Cations(as picrates)

General trend for cations

N(n-pentyl)₄⁺ > PPh₄⁺ > N(n-butyl)₄⁺ > N(n-propyl)₄⁺ > NEt₄⁺ > NMe₄⁺