Simple low-cost tungsten-coil atomiser for electrothermal atomic absorption spectrometry

Abstract

The development of a low-cost filament furnace for use with electrothermal atomic absorption spectrometry (ETAAS) is described. The filament furnace is based on the utilisation of a cheap tungsten coil originally produced with high precision for the halogen bulbs of photo-projectors. All elements determinable with a tube furnace can also be determined with the filament furnace, with the exception of Mo (an impurity of W). The elements Al, Ba, Cd, Co, Cr, Eu, Mn, Ni, Pb, Si, Sn, Ti and V were investigated in more detail. The system incorporating the filament furnace proved to be of comparable sensitivity to the system involving a commercially available graphite furnace when determining Cd, Co, Cr, Eu, Mn, Ni, Pb, Sn and V. However, Al, Si and Ti are less easy to determine compared with the graphite furnace technique. This can be explained by the steep temperature gradient on the surface of the tungsten filament. On the other hand, Ba can be determined with a higher sensitivity, by about one order of magnitude. A mixture of 90% Ar and 10% H₂ was used as purge gas.

The practical application of the system is shown by the determination of trace elements in synthetic urines.