Qualitative emission spectral analysis:

The atomic spectral lines are very narrow with respect to the whole spectral range, yet there is a possibility of encountering line coincidences. It is important to note that more than 200 000 lines in the spectral range of 200-400 nm have been tabulated and assigned to different elements of the periodic table. In addition there are a large number of lines in other regions also. Thus, high-resolution spectrometers have to be used for the qualitative evaluation of the spectra. The unambiguous detection and identification of a single noninterfered atomic spectral line of an element is sufficient to indicate its presence in the analyte sample.  However, use of more than one line is necessary to conclude the presence or absence of an element.

Qualitative emission spectral analysis is quite easy when the spectra are recorded on a photographic plate or with a scanning monochromator. A number of atlases are available for the photographically recorded spectra; spectra are reproduced and the most sensitive lines are indicated in these atlases. The spectrum of an analyte can then be compared with the collated spectra in the atlases to identify it.  These are also useful for the practising analytical chemist.

In order to facilitate quantitative determinations,  spectral line tables, in which the wavelengths of the spectral lines together with their excitation energy and a number indicating their relative intensity for a certain radiation source are tabulated. These are available for different sources, such as arc and spark sources, but also in a much less complete form for newer radiation sources such as inductively coupled plasmas.