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The effect of an ethanol-loaded sample solution when aspirated into an inductively coupled plasma was investigated. It was found that increasing concentrations of ethanol resulted in a proportional increase in the intensity of the Ha line. The electron density, as calculated both with and without Abel inversion, also increased with increasing ethanol concentration. Mass flow rates of the aerosol increased with an increase in the ethanol concentration. This resulted in a relative mean drop-size distribution which increased from 2 ym for water to 24.5 pm for 25% ethanol. A mechanism is suggested to explain the increases encountered.

Changes to the fundamental and analytical parameters of a plasma have been investigated when ethanol has been added to aqueous or organic solutions. Excitation temperature, electron number density, and intensity of the H(alpha) line increased when ethanol has been added to aqueous solutions, while an electron density decrease and signal reduction have been found when ethanol has been added to xylene. The sensitivity has been improved for all ethanol concentrations when water has been the solvent, but the reverse has been found for xylene solutions.

An attempt has been made to identify molecular species that are formed during the atomization cycle of Si in electrothermal atomic absorption spectrometry. Clear evidence has been obtained that two molecular species are formed, presumably SiO and Sic2. In order to gain an insight into the reactions whereby these molecular species are formed and Si atoms from these species, the effect on the signal of the addition of 02, C 0 2 , CO and H2 to the purge gas was investigated. By using the results of these experiments, a mechanism for the atomization of Si in the graphite furnace atomizer is proposed.