Atomic Distribution in Flames

The neutral atom distribution is quite variable in the flames of both premixed and total-consumption burners. Therefore the maximum absorption signal from a flame cell will only be obtained if the optical path traverses 

FIGURE 10-16. Wang laminar flow burner head. [Courtesy Mid-Continent Scientific, Inc.] 

FIGURE 10-17. Comparison of the calibration curves of copper using the Wang burner head and a standard single-slot burner. 

A large number of fuel-oxidant combinations have been used for atomic absorption spectroscopy, including air-propane, air-acetylene, air-hydrogen, oxygen-propane, oxygen-acetylene, oxygen-hydrogen, and nitrous oxide-acetylene. Many variations in the ratio of fuel to oxidant also have been used. 

Flame temperatures and fuel-to-oxidant ratios are two of the most important parameters to consider when using a flame as an atomic absorption sample cell. Table 10-2 lists maximum temperatures attainable with various combinations of fuel and oxidant. 

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