Graphite Furnace Atomic Absorption Spectrometry

Research Group for Atomic Spectrometry

Integrated contact cuvette, designed at this department

Graphite Furnace Atomic Absorption Spectrometry

Graphite furnace atomic absorption spectrometry (GFAAS) is also known by various other acronyms, including electrothermal atomic absorption spectrometry (ETAAS). Briefly, the 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 figure at the top of this page shows a graphite tube designed by Wolfgang Frech and Bruno Hütsch (retired from Ringsdorff-Werke GmbH, Bonn, Germany). Light (red lines) from a source emitting wavelengths specific to the element of interest passes through the tube, where it will be absorbed by free atoms produced during heating of the tube.

Fundamental studies
The purpose of these studies is to contribute to our understanding of the processes leading to free atom production and signal formation in GFAAS. Ultimately, such investigations will assist in the designing of optimal GFAAS systems, and in obtaining the best possible performance from the instrument during routine analysis.
Instrumental developments
Although 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.
Analytical applications
Within the group, GFAAS has been applied to the determination of trace metals in a wide range of sample types, in various fields:-

Clinical and biological materials: blood, urine, synovial fluid

Environmental samples: natural waters, sediments, plant materials

Industrial materials: steels, petroleum products

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This document was last updated on July 31, 1996.

Research Group for Atomic Spectrometry

Graphite Furnace Atomic Absorption Spectrometry

Fundamental studies

Instrumental developments

Analytical applications