History of Ion Chromatography
Chromatography is a method for separating mixtures
of substances using two phases, one of which is
stationary and the other mobile moving in a particular
direction. Chromatography techniques are divided
up according to the physical states of the two
participating phases. The term Ion Exchange Chromatography
or Ion Chromatography (IC) is a subdivision of
High Performance Liquid Chromatography (HPLC).
Definition of Ion Chromatography
A general definition of ion chromatography can
be applied as follows: "ion chromatography
includes all rapid liquid chromatography separations
of ions in columns coupled online with detection
and quantification in a flow-through detector"
How it works
A stoichiometric chemical reaction occurs between
ions in a solution and a solid substance carrying
functional groups that can fix ions as a result
of electrostatic forces. In anion chromatography
these are quaternary ammonium groups. In theory
ions with the same charge can be exchanged completely
reversibly between the two phases. The process
of ion exchange leads to a condition of equilibrium;
the side to which the equilibrium lies depends
on the affinity of the participating ions to the
functional groups of the stationary phases.
Ion Chromatography Know-how from Metrohm
More theoretical background can be found in our
free monograph Ion Chromatography (8.732.2003)
or in Practical
Ion Chromatography which can be ordered
free of charge at your
local distributor, the later also online. |
