Investigation of reactions involved in graphite furnace atomic absorption procedures: Part 12. A study of some factors influencing the determination of selenium
✍ Scribed by Anders Cedergren; Ingela Lindberg; Erik Lundberg; Douglas C. Baxter; Wolfgang Frech
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 944 KB
- Volume
- 180
- Category
- Article
- ISSN
- 0003-2670
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✦ Synopsis
An experimental and theoretical study of various factors influencing the determination of selenium by graphite furnace atomic absorption spectrometry (g.f.a.a.s.) is reported. It is shown that the atomization efficiency can be increased as compared to the L'vov platform techmque by means of a constant temperature furnace as a consequence of the possibility of choosing a higher atomization temperature. This is explained by means of high temperature equilibrium calculations, which include the formation of the thermodynamically relatively stable gaseous diselenium, hydrogen selenide and selenium sulphide. The extent of losses of selenium during thermal pretreatment was established by measurements with 75Se for different types of selenium compounds, Se(-II)-methionine, selenite and selenate, iin aqueous solutions as well as in chloride and sulphate matrices. It is shown that the 'addition of 20 Mug of nickel is effective in stabilizing Se(IV) and Se(V1) in the presence of sodium chloride, sodium sulphate and pure water. However, in the presence of both an organic matrix (glucose) and sodium chloride, nickel is shown to lose its stabilizing effect.