Effect of halogenated solvents on iron atomization in graphite-furnace atomic-absorption spectroscopy.
When an iron solution in an organic solvent is examined by atomic-absorption spectroscopy, the signal decreases to below that for a comparable aqueous solution. This effect is most pronounced for halogen-containing solvents because of volatility of FeCl(2), and a change in the atomization curve with a shift towards higher temperatures for atomization. When the cuvette is pretreated with halogenated solvent a double peak is observed. The first peak corresponds to that found for aqueous solvents, the second may be correlated with the peak for iron in a halogenated solvent. The peaksplitting effect of such a solvent increases with halogen:hydrogen ratio in the solvent. The halogen penetrates the structure of the graphite cuvette and probably forms strong carbon-haloge. compounds which modify the atomization conditions for iron. When water is introduced hydrogen halide is formed, which removes the excess of halogen from the atomization region.
Karwowska
R
R
Department of Chemistry, University of Warsaw, Warsaw, Poland.
Bulska
E
E
Hulanicki
A
A