The distinction between the
distribution constant(
) and the
partition constant(
) or the concentration distribution ratio
(
)
is reaffirmed and it is recommended that the terms
partition constant,
partition coefficient and
extinction constant should not be used as synonyms for the (analytical)
distribution ratio,

. A distinction is drawn between the terms solvent and diluent, and the term
extractant is now restricted to the active substance in the solvent (i.e. the homogeneous '
organic phase' which comprises the
extractant, the diluent and/or the modifier) which is primarily responsible for the transfer
of solute from the '
aqueous' to the '
organic' phase.