The radiofrequency (rf) inductively coupled plasma (ICP) has become a widely used tool for multielement atomic emission analysis. Investigation of excitation processes in spectroscopic systems is very important for the full realization of the analytical utility of any new tool. This is particularly true in the case of plasma sources, where the excitation mechanisms have been shown to be different from those in flames. Mermet and Trassy designed a special rf plasma torch atomic absorption measurement, and Wendt and Fassel determined elements which are strong monoxide formers by atomic absorption measurements in an rf plasma. Using electrodeless discharge lamps as the primary excitation source, Montaser and Fassel reported atomic fluorescence in the ICP tail plume (3 to 5 cm above coil). Higher signals for fluorescence than emission were obtained for cadmium, zinc, and mercury, but a special torch configuration was required.
B. D. Pollard, M. B. Blackburn, S. Nikdel, A. Massoumi, and J. D. Winefordner, "Atomic Fluorescence Spectrometry in the Inductively Coupled Plasma with a Continuous Wave Dye Laser," Appl. Spectrosc. 33, 5-8 (1979)