Electrothermal atomization variables

After a brief period of use, the graphite tubes and rods that are commonly employed In electrothermal atomizers begin to deteriorate, and their electrical characteristics become subject to drift (7,9,47). This is one of the most troublesome sources of analytical variability. Maessen et al (47) demonstrated that the properties of graphite (e.g. porosity ancl conductivity)... 

Gas chromatography coupled with AAS has been the most popular hyphenated technique for the speciation of metals and organometals. Among different atomizer designs employed in coupling GC with AAS, electrothermal atomization, especially the electrother-mally heated quartz tube, is preferred because of its high sensitivity, simple operation, and low cost [6]. The quartz tube (—100 X 10 mm inner diameter) is usually constructed in house and wrapped with Nichrome resistance wire and ceramic isolation material. A thermocouple is attached to the surface of the quartz burner for temperature control (Fig. 1). If necessary, hydrogen and air can be supplied from side arms of the burner. The furnace can be heated to more than 1000°C by means of a variable transformer. 

Variables of solid sampling with electrothermal vaporizers and atomizers... 

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