AAS - Graphite Furnace

Graphite furnace atomic absorption spectrometry (GFAAS) is also known by various other acronyms, including electrothermal atomic absorption spectrometry (ETAAS).

This technique is based on the fact that free atoms will absorb light at frequencies or wavelengths characteristic of the element of interest (hence the name atomic absorption spectrometry).

Within certain limits, the amount of light absorbed can be linearly correlated to the concentration of analyte present. Free atoms of most elements can be produced from samples by the application of high temperatures. In GFAAS, samples are deposited in a small graphite tube, which can then be heated to vaporize and atomize the analyte.

The first GFAAS systems were built 30 years ago, there is still room for improvement. An ideal graphite furnace should fulfill the following requirements:
A constant temperature in time and space during the interval in which free atoms are produced;
quantitative atom formation regardless of the sample composition;
separate control of the volatilization and atomization processes;
high sensitivity and good detection limits;
A minimum of spectral interferences. Developments in graphite furnace design made at Umeå University have been incorporated in many modern commercial instruments.