The Furnace

The electrothermal vaporizer is a graphite cylinder having a diameter of 8 mm and being about 30 mm long. It has a little radial hole which offers the way to introduce the sample into the atomizer. I wouldn't wish to be part of the sample which is put into the furnace because after inserting the sample its atoms are scientifically abused as follows:

1. the temperature is raised to vaporize the solvent. The metal atoms don't yet know what's going on, they just observe that there is less and less solvent around them. After a while they observe that all the solvent has gone.
2. the second step is the calcination of the sample.
3. the temperature is raised in order to atomize the sample. This is the step in which life becomes really difficult inside the furnace because the temperature reaches 2500 - 3000 ºC depending on the element being analysed. Just like in the flame the sample is transformed into an atomic cloud. This is the step in which the signal must be measured because now the atoms can absorb radiation.
4. the clean-up is the final step of this programmed extermination. The truth is that if there is no such step the furnace will have memory effects, that is some of the atoms will get out of the furnace at another time, disturbing the next analyses.

The only good thing in this method is the Ar flow used to protect the furnace from oxidation. It is felt by the atoms as a nice, cooling wind. Unfortunately this flow isn't used in the atomization interval because it would carry the sample out of furnace.

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