Thesis (MTech. degree in Chemistry)--Tshwane University of Technology, 2008. / This work is aimed at experimental verification of the theory about the advantages of the
two-step sample vapour release in a fast-heated ballast furnace. The term “ballast” was
introduced earlier in electrothermal atomic absorption spectrometry, as an alternative to a
platform to describe a compact body of refractive material loosely located on the bottom
of a tube furnace atomiser. The thermal behaviour of the ballast furnace is similar to that
of the platform, but without restriction created by the platform area. Compared with the
flat or concave platform, a compact ballast of similar mass to the platform should have
less impact on gas temperature because of the smaller surface area. The theoretical
predictions concerning atomisation efficiency in the fast-heated ballast furnace were
examined by the determination of metals in organic and inorganic matrices using a
Quantum Z.ETA atomic absorption spectrometer. The instrument provided fast heating
of the tube atomizer, 10 K ms-1.
It is shown that in the employed ballast furnace the vapour released into the gas phase
occurs after interim condensation on the ballast. For the samples of tetraethyllead, base
oil and aqueous solutions of various metals, analytical signals are observed after
stabilisation of tube temperature, independent of volatility of the analyte and level of
temperature setting. For those samples, a high gas phase temperature provides complete
recovery of the analyte without involvement of chemical modifiers and the reduction of
spectral interferences from chloride matrices.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1000349 |
| Date | January 2008 |
| Creators | Banda, Maria Fenzile |
| Contributors | Katskov, D.A., Ngobeni, P |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | |
| Rights | © 2008 Tshwane University of Technology |
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