Furnace Gases; Special Gas - PerkinElmer AAnalyst 700 User Manual

Laboratory Requirements

Furnace gases

Inert gas
The graphite furnace requires a supply of inert gas to prevent the tube and the
analyte atoms from being oxidized when the tube is heated.
Argon is the recommended inert gas.
If you cannot obtain argon, you can use purified nitrogen, but nitrogen does not
provide such efficient protection as argon at temperatures above 2000 °C.
Nitrogen can also react with the samples and the graphite tube at typical
atomization temperatures.
Warning: Toxic Gases
If you use nitrogen as the inert gas, toxic cyanogen gas (CN)
when the furnace temperature is above 2300 °C.
 Make sure that the main laboratory fume ventilation system removes all
gases and fumes emitted by the furnace.

Special gas

For some applications you may want to use a special gas. A typical example is the
use of air during one of the pyrolysis steps to better ash organic materials.
6-14
W6.1
will be produced
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