The temperature of atomic vapor in graphite furnace atomic absorption spectrometry

The excitation temperature of the atomic vapor arising from analyte atomization in two commercial graphite furnaces was measured by an optical two-line absorption technique. In, Ga, Fe and Sn were employed as thermometric species. Deviations from thermal equilibrium with the graphite walls increase in a roughly linear manner with time, reaching as high as 1300 K before the atomic population is lost. This time-dependent temperature difference is a function of the rate of heating of the atomizer as well as the thermometric species. The influence of a hydrogen diffusion flame in determining excitation temperatures is minimal. Ionization of analyte elements in graphite electrothermal atomizers is negligible, possibly because of the effect of background electrons generated within the furnace.Peer reviewed: YesNRC publication: N