Method development for graphite furnace analysis

Obviously, the basic procedure and the measures taken in method development for GF AAS are identical for LS AAS and HR-CS AAS, as the same atomizers and control units are used. However, the special features of the latter technique, particularly the fact that the spectral environment of the analytical line becomes visible at high resolution, facilitate method development tremendously. In addition, as dynamic signals are generated in the 

Thallium is one of the most difficult elements for GF AAS, at least when it has to be determined in complex matrices, as will be shown in more detail in Sections 8.2.6 and 8.2.7. Thallium forms a chloride that is volatile at temperatures above 400 °C and easily lost without being atomized, as the gaseous molecule HCl is thermally very stable. Palladium, the most frequently used modifier to avoid such losses, has an absorption line close to the T1 line, causing a spectral interference. Iron, a frequent concomitant in many samples, also has an absorption line close to the T1 line. Finally, sulfur-containing samples produce a molecular absorption spectram with a pronounced rotational fine stfucture, which is another source of spectral interferences [141]. 

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