Abstract
	On the evolution of free atoms in the tungsten furnace may participate a several types of atomisation reactions. Atomization reactions may take place either in homogeneous or heterogeneous phase. It is assumable that reactions in homogeneous phase are more significant from view of kinetics and hence they will be more rapid than heterogeneous ones.
	The assumed reactions, in view of phases in which they take place, may classify for four types, while kinetically more significant will be reactions occuring in the gaseous phase, e.g. in the inner volume of the furnace. For atomization of easily volatile analytes, however, heterogeneous reaction betwen gaseous compounds and betwen condensed salts of analytes and the solid surface of the furnace become significant. 
The following four types of  interaction may be assumed:
	heterogeneous reactions  of the metallic surface of tungsten atomizer with a condensed constituents of the system,
	heterogeneous reactions of the metallic surface of tungsten atomizer with a gaseous analyte constituents and other gaseous constituents of the system,
	heterogeneous reactions of a condensed analyte constituents with a gaseous contituents of the system, especially with hydrogen contained in the protective atmosphere, and
	homogeneus reactions in gaseous phase, with participation of constituens of protective atmosphere, evaporated forms of analyte constituents and other gaseous- evaporized constituens of the system
	If cadmium  or cobalt nitrate is used for atomization,  elemental forms of analytes arise over dissociation temperature of corresponding nitrates of analytes. Nitrates may thermally dissociate, too, and analyte in elemental form arise by reduction of analyte oxides by hydrogen or tungsten. 
	Calculations of Gibbs energy values for some volatile analytes proved that free atoms of volatile analytes can be generated at atomization temperature directly from metallic form of particular elements, by reduction of newly formed analyte oxides by hydrogen and/or by reaction of tungsten and hydrogen, respectively, while reduction of newly formed tungsten oxides by hydrogen contained in the protective gas atmosphere takes place in some cases.
	This study gives ideas about assumed types of interaction and chemical reactions by electrothermal atomization in the tungsten atomizer.