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Chapter 10
Liquid Chromatography/Atomic Spectroscopy (LC/AS) Tandem Systems

The association of a spectrometer with a liquid chromatograph is usually to aid in structure elucidation
or the confirmation of substance identity. In contrast, the various forms of atomic spectroscopy are
almost exclusively employed in elemental analysis. The different atomic spectroscopic techniques offer
high element sensitivity, unambiguous element identification and, if all the different forms of the
technique are included, can accommodate samples contained in almost any type of matrix. Although
atomic spectroscopy can easily and accurately identify the element, it can neither determine the form in
which the element is occurring, nor can it determine its valency state. As the majority of analyses
involving element identification, include identifying the chemical form of the element, the simple
atomic spectroscopic analysis is inadequate and some other additional technique is necessary. A
preliminary separation process allows the different forms of the element to be isolated, and the
individual components, that contain the elements of interest, can then be identified by the appropriate
form of atomic spectroscopy. Ideally the two techniques are joined, and the separation and
identification carried out sequentially as with (LC/AS or GC/AS) tandem instruments.

Sample introduction in atomic spectroscopy, whether it be to a flame atomic absorption spectrometer, a
graphite furnace absorption spectrometer, or an ICP/MIP atomic emission spectrometer, usually
involves the nebulization of the sample dissolved in some liquid, and the spray is then passed into the