UV-Visible Molecular Spectrometries

4 OTHER SPECTROSCOPIC METHODS 7.4.1 UV-VisiBLE Molecular Spectrometries 

FIG U RE 7.20 Schematic representation of the main processes involved in the interaction of UV-visible radiation with matter. 

Atomic emission occurs when an atom gets excited by nonradiative means (usually in a flame) and emits a photon, returning to the ground state. This technique has been, and is still, used for the determination of alkaline and alkaline earth elements, which have efficient emission at normal flame temperatures (Wright and Stuczynski 1996). For most other elements, higher temperatures are required, which can be obtained in inductively coupled plasma (ICP), methods known as inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). An ICP is obtained by passing ionized Ar 

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