MODERN DETECTION TECHNIQUES IN ION CHROMATOGRAPHY
Viehweger, K.H., S. Czyborra and A. Wille
Metrohm AG; Herisau; Switzerland
Today Ion Chromatography is a well established technique when the analysis of anions and cations is
required. Anions are analyzed both with and without chemical suppression, cations using non
suppressed set up. Common is the type of detection used: Conductivity.
Conductivity detection is used cause of it's simplicity, ease of use and high sensitivity. But other
detection techniques are used in ion chromatography as well. In combination with the ion exchange
separation that characterizes ion chromatography, electrochemical detectors including pulsed
amperometric detectors, refraction index detectors or UV/Vis detectors are commonly used.
Recently so called hyphenated techniques have been introduced. This is the combination of ion
chromatography with either Mass Spectrometry (IC/MS) or Inductively Coupled Plasma Mass
Spectrometry IC-ICP/MS.
While ion chromatography typically allows direct analysis of single digit ppb (µg/L) levels of anions
and cations or single digit ppt (ng/L) levels when pre concentration is used these hyphenated
techniques allow even lower detection levels. In addition for some applications they eliminate the
influence of a disturbing matrix. Hyphenated techniques can as well be used for ion speciation and
separation of organic and inorganic species of the same atom.
The paper presented gives an overview on these state of the art detection techniques in ion
chromatography.