A solid or liquid, inorganic or organic substance containing exchangeable ions with
others of the same charge, present in a solution in which the ion exchanger is considered
to be insoluble. It is recognized that there are cases where liquid exchangers are
employed and where it may be difficult to distinguish between the separation process
as belonging to
ion exchange or liquid-liquid distribution, but the broad definition given here is regarded as
that which is most appropriate. A monofunctional ion exchanger contains only one type
of ionogenic group, a bifunctional ion exchanger two types and a polyfunctional ion
exchanger more than one type. In a macroporous ion exchanger the pores are large compared
to atomic dimensions.
Source:
PAC, 1993, 65, 819
(Nomenclature for chromatography (IUPAC Recommendations 1993))
on page 855