Atomic Absorption Spectroscopy

Intensity will be reduced if the element is present because part of the light will be absorbed by its atoms. The concentration of the element in the sample directly correlates with the amount of light absorbed. By measuring the quantity of light that is absorbed, the AAS instrument creates a concentration number that can be used to calculate how much of the element is present in the sample.

 Due to the method's great sensitivity, it can identify minute concentrations of various elements in a variety of materials, including gases, solids, and liquids. Environmental monitoring, food and beverage analysis, clinical chemistry, as well as several other fields of study and business, all make extensive use of AAS.

Principle of AAS

When a beam of EMR Electromagnetic radiations of characteristic wavelength is pass through the vaporized atom present in flame or plasma then the atom absorbs these radiations and decrease its intensity which is directly proportional to the number of atoms in the ground state.

There are several types of atomic absorption spectroscopy (AAS), which are differentiated by the source of the light and the method of introducing the sample into the instrument. Some common types of AAS include:

Flame atomic absorption spectroscopy (FAAS): 

This is the most common type of AAS, where the sample is introduced into a flame where it is vaporized and atomized. The light source is typically a hollow cathode lamp specific to the element being analyzed.

  Graphite furnace atomic absorption spectroscopy (GFAAS): 

This type of AAS uses a graphite furnace to vaporize and atomize the sample, which is then analyzed using a light source such as a hollow cathode lamp.

 

  Cold vapor atomic absorption spectroscopy (CV-AAS): 

This technique is used to determine the concentration of mercury in samples. The sample is reacted with a reducing agent to convert any mercury present into elemental mercury, which is then vaporized and analyzed using AAS.

  Electrothermal atomic absorption spectroscopy (ETAAS):

This technique is similar to GFAAS, but uses a heated graphite tube to vaporize and atomize the sample.

Hydride generation atomic absorption spectroscopy (HGAAS):

 This technique is used to determine the concentration of elements such as arsenic, antimony, and selenium. The sample is reacted with a reducing agent to convert the element of interest into a gaseous hydride, which is then analyzed using AAS.

 

v  These are just a few examples of the types of AAS that are available. The specific type of AAS used depends on the sample being analyzed and the element of interest.