Recent developments in atomizers for electrothermal atomic absorption spectrometry

Abstract

This review first describes general requirements to be met for suitable base materials used to produce electrothermal atomizers (ETAs). In this connection the physical and chemical properties of adequate types of graphite and metals are discussed. Further, various atomizer designs, their temperature dynamics during atomization and general performance characteristics are critically reviewed. For end-heated Massmann-type atomizers, discussions are focused on recent developments of, e.g., contoured tubes to achieve improved temperature homogeneity over the tube length, second surface atomizers to realize temporally isothermal atomization and tubes with graphite filters to reduce interference effects. The state-of-the-art of platform equipped, side-heated atomizers with integrated contacting bridges are characterized mainly with respect to heating dynamics, as well as susceptibility to interference- and memory effects. In contrast to end-heated ETAs, the tube ends of side-heated ETAs are freely located in the furnace compartment and, as a consequence of this configuration, convective gas flows can easily appear. The magnitude and effect of these flows on analytical performance are discussed and measures are suggested, permitting operation under diffusion controlled conditions. A critical comparison of classical constant temperature atomizers with state-of-the-art platform equipped ETAs is made and from this it is concluded that future ETA developments are likely to involve only minor modifications aiming at, e.g., the reduction of cycling times or the improvement of tube surface properties.

Trace metal analysis in arctic aerosols by an inductively coupled plasma-time of flight-mass spectrometer combined with an inductively heated vaporizer

“…The procedure for ETV, including the instrumentation and readily handling of small sample volumes, is well-known from graphite furnace atomic absorption spectrometry (GFAAS) [15,16]. It is mostly easily adapted for ETV-ICP-MS [17 -19] even if the tube form comprises some disadvantages: (i) during the period of heating the tube an argon flow carries the vaporized sample out of the tube through a chilled electrical contact upon which vaporized species may condense, (ii) the electrical heating needs an excellent contact between tube and contact cones provided by the precision of cones and a constant contact pressure, (iii) the relatively high graphite volume needs to clean.…”