Atomisation efficiency and over-all performance of electrothermal atomisers in atomic absorption, furnace atomisation non-thermal excitation and laser-excited atomic fluorescence spectrometry. Plenary lecture

Abstract

The atomisation efficiency of electrothermal atomisers using cup or tube geometries is estimated by model calculations. Tube atomisers operated at atmospheric pressure have an efficiency of more than 50% whereas that of the low-pressure FANES system and the cup atomiser is typically less than 5%. The results of the calculations are supported by atomic absorption measurements. Using these data, the minimum number of analyte atoms detectable within the atomisers using LAFS, FANES or GFAAS has been calculated to be in the region of 10^–4–10⁹. The concentration of the matrix species to be expected in the gas phase of the ETAs is estimated. Gas-phase interferences should be less using the cup and low-pressure atomisers compared with the usual tube furnace because of the longer residence time in the latter.