Graphite Furnace Atomic Absorption Spectrometry
- Graphite Furnace is based on the same principles as Flame Atomic Absorption Spectrometry.
- The main difference is in the atomization of the sample.
- Instead of the Flame, the Graphite Furnace uses an electrothermal atomizer which is a small graphite tube.
- Graphite Furnace is a more sensitive technique for the determination of metals. Flame AAS can analyse samples in the ppm range but the Graphite Furnace can analyse concentrations in the ppb range.
- The Graphite tube is where the atomization takes place.
- A few microlitres of sample is injected into the tube.
- The temperature of the tube increases over a matter of seconds and can reach up to 3000oC depending on the element being analysed.
- The atomization of the sample takes place in milliseconds.
- The absorption of the atomic vapor is then measured in the tube immediately above the heated surface.
Uses of Graphite Furnace Atomic Absorption
- The Graphite Furnace is used for the same tests as the Flame Atomic Absorption Spectrometer.
- The Graphite Furnace is more sensitive than the Flame AAS so it can be used for trace metal analysis in the ppb range.
- For some metals which can cause poisoning in relatively small quantities it is vital to test in the ppb range for their presence in food and water.