TYPES OF AAS aka Atomic Absorption Spectroscopy

Atomic Absorption Spectroscopy is a commonly used technique in finding out the concentrations of metals or metallic elements present in the given material. It is common knowledge that different elements absorb different wavelengths of light. This is the same principle behind Atomic Absorption Spectroscopy or AAS.

Tutorials from websites like Lab-Training.com greatly aid in developing the understanding of a person about this subject. There are four different methods to perform AAS.

They are: Flame AAS (F AAS), Cold AAS (CV AAS), Hydride-generation AAS (HG AAS), and Graphite AAS (GF AAS).

Flame Atomic Absorption Spectroscopy (F AAS):

It is well known that atoms in the ground state absorb different wavelengths. A light beam is passed through the fire. This light beam has such a wavelength that atoms can absorb it in the ground text. Through this, the decreasing intensity of light can be measured.

To conduct this experiment, a liquid sample that is aspirated and aerosolized is required. It must be mixed with combustible gases like acetylene. This is now ignited in a flame. When metals present in the given sample are exposed to heat, they absorb light at different wavelengths or frequencies.

The wavelengths that were absorbed can be compared to the already existing data of which atom absorbs which wavelength. The metals present in the given liquid sample can be determined using the results from this experiment.

Flame absorption spectroscopy is most suitable for measuring and identifying a minimal range of metals present in the given liquid sample. It is generally used for the analysis of biological fluids like saliva, plasma, urine, and blood.

Cold Vapor Atomic Absorption Spectroscopy (CVAAS):

Cold Vapor AAS (CVAAS) is a technique used to detect the presence of mercury. It is used to detect the presence of mercury in drinking water. Mercury is fatal for living organisms even in trace amounts as it is a heavy metal.

It works by analyzing the sample’s absorption spectra in which chemicals of interest absorb energy to create distinct spectral lines. The main advantage of using CV AAS is that it is far more sensitive and efficient than any of the techniques that preceded it.

It is also cheaper than any other previous techniques, making it widely available for general use. This technology is omnipresent in every city and is a tool that helps us receive clean drinking water.

Hydride Generation and Graphite Furnace Atomic Absorption Spectroscopy (HG AAS and GF AAS):

Hydride Generation AAS is a methodology applied as a part of a chain reaction in which a reduction reaction occurs to convert a particular metal to its volatile state. It is used widely in elements belonging to groups 8 and 11.

It is a highly sophisticated technique and requires a high standard of quality control and specialized equipment. These high standards make it necessary to entrust this with professionals.

The use of Hydride generation technology can be seen in research and industrial aspects. Presently, they are widely used in the quantitative analysis of selenium in meat.

It is vital because the high content of selenium is proven to have adverse effects on human beings. It is worth noting that there is more concentration of selenium in meat than ever due to excessive use of antibiotics in poultry and cattle.

A graphite furnace is a tool that uses electrothermal atomizing to heat objects. It is different from a traditional furnace because of its use of electrothermal atomizing. And that makes it an ideal choice for the determination of metals.

While a flame furnace can only determine metals in the ppm range, a graphite furnace can identify the same metals in the ppb range. It makes this piece of machinery highly efficient and reliable.

The functioning of a graphite furnace is quite complex in simple terms. When few minute particles of the sample are injected into the furnace, it becomes vapor almost immediately due to extreme heat present in the furnace chamber.

The vaporized metals are then absorbed and measured in a tube right above the furnace. Graphite Furnace and Hydride Generation AAS are often used together. They are predominantly used to detect selenium in meat.

The growing demand for meat and declining pasturelands to feed animals forces farmers to resort to chemical implements to improve the yield, but this comes at the cost of human health.

And strict regulatory measures are to be taken to provide healthy and nutritious food to all. And machinery like these has vital roles to play in keeping our food safe and healthy.