Speciation of sulfur in individual aerosol particles from work places by wavelength-dispersive electron-probe microanalysis.
The oxidation state of sulfur has been determined by measuring the energy shift of the S K(alpha) line by wavelength-dispersive electron-probe microanalysis. On flat polished samples the energy shift between sulfate (S(+6)) and sulfide (S(-2)) was 1.3 eV, in good agreement with previous literature data. The observed energy shift of the S K(alpha) line is dominated by the change of the valence state of sulfur--the effects of co-ordination geometry and nearest neighbours are small. The relationship between the energy shift of the S K(alpha) line and the oxidation number of sulfur is linear, to a first approximation. The effect of particle geometry on the position of the S K(alpha) line is usually small and introduces an error of approximately half an oxidation number. The apparent sulfur valence states observed for individual aerosol particles from work places in a nickel refinery are highly variable and most probably result from different mixtures of the two end-members sulfide and sulfate.
Höflich
B L W
BL
Institute of Material Science, Technical University of Darmstadt, Petersenstr. 23, 64287 Darmstadt, Germany.
Weinbruch
S
S
Ortner
H M
HM