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Ion Chromatograph for the Analysis of Water

The goal of ion chromatography (IC) is to separate a water sample into individual peaks on a band. Each peak represents an ion, and the area of that peak represents the concentration. Ions that are typically determined on an IC include anions (fluoride, chloride and bromide), cations (sodium, potassium and calcium) and organic acids (humic, oxalic and acetic).

  1. Principles

    • Ion chromatography measures concentrations of different compounds or elements found in water. Each ion is individually extracted by an eluent, a liquid that absorbs ions, and separated through a resin-coated column. The time that it takes for the ion to appear as a peak on a band determines what that ion is.

    Applications

    • There are hundreds of different types of applications for ion chromatography being developed everyday to be used in the environmental, manufacturing and food industries. Drinking and waste water are some applications for IC used in environmental labs, while the food industry utilizes it for wine making or milk production. Other applications include detecting explosives, pesticides and metals.

    Analysis

    • Operating an ion chromatography system can be compared to an elite home theater system. There is a main system where the separation takes place (TV), an auto sampler to put samples into (DVD player) and a computer that controls the entire system (remote control). The amount of time for each sample determines what application and eluent is being used. Anions can take up to 30 minutes per sample, whereas cations may take about 15 minutes per sample.

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