Dissociation of the sample into atoms or ions

3 DISSOCIATION OF THE SAMPLE INTO ATOMS OR IONS Excitation on excited Emission 

OES requires high performance instruments capable of locating weak intensity lines in close proximity to other much more intense. This is why preference is given to spectrometers having a broader dynamic range. 

To convert a sample to free atoms, excited or ionized, various procedures are employed based upon gas plasmas, sparks, lasers or glow discharges. 

The most common instruments for OES contain a plasma torch (inductively 

A plasma is a highly energized cloud of gaseous ions and their electrons. Considered to be the fourth state of matter, it is formed by isolated atoms in equilibrium between their neutral and their ionized states (more than 2 per cent) and with the associated electrons (10 /cm ) which assure an overall neutrality of the medium. 

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