Atomic absorption spectrometry (AAS) is an analytical technique that measures the concentrations of elements in a sample. It works by heating the sample so that the elements are atomized and exposed to light from a hollow cathode lamp tuned to the wavelength absorbed by the element. The amount of light absorbed can then indicate the concentration of the element in the sample. AAS is useful for trace metal analysis in applications such as environmental monitoring, food safety testing, and clinical analysis.

1. Atomic absorption spectrometry
AAS
Dr. G. D. HANDE

3. Atomic absorption spectroscopy
was first used as an analytical
technique, and the underlying
principles were established in the
second half of the 19th century
by Robert Wilhelm Bunsen and Gustav
Robert Kirchhoff, both professors at
the University of Heidelberg, Germany.

4. Atomic absorption
spectrometry (AAS) is an analytical
technique that measures the
concentrations of elements.
Atomic absorption is so sensitive
that it can measure down to parts per
billion of a gram in a sample.

6. The technique makes use of
the wavelengths of light specifically
absorbed by an element.
They correspond to the
energies needed to promote
electrons from one energy level to
another, higher, energy level.

14. Atomic absorption Spectroscopy Instrumentation:
Atomic absorption spectroscopy unlike other spectroscopy
methods has two additional requirements like a specially
designed lamp to produce light of desired wave and a
burner to prepare the sample for absorption of light.
The instrumentation includes:
1. The burner to dry the sample and produce atoms.
2. Sample container.
3. Fuel and oxidant to burn the sample by heat.
4. Hallow cathode lamp to produce light of desired
wave length.
5. Detector to detect the absorption intensity.
6. Amplifier and data recorder.

16. The burner: Here sample from the
capillary rises to the tip of burner where it
is burned with flame produced by the fuel
and oxidant combination. The sample
after evaporation leaves a fine residue of
neutral atoms.
Sample container: This is a beaker like
container of sample which is placed below
the burner preferably. A capillary tube
drains the sample to the tip of burner.

17. Fuel and oxidant:
This is a very important part of
entire process to be remembered. If the
heat produced is not sufficient then the
sample doesn’t form neutral atoms.
If the heat of burner is more, the
sample molecules may ionize instead of
forming atoms. So both are undesirable
for experimentation.

18. Hence a proper combination
of fuels and oxidant are to be used
to produce recommended
temperatures.
Commonly used flues include
propane, Hydrogen and acetylene ad
oxidants are mostly air or oxygen.

23. It is specially useful to analyze trace metal
elements in plasma and other body fluids.

24. Agriculture – analyzing soil and plants
for minerals necessary for growth
Chemical – analyzing raw
chemicals as well as fine chemicals
Environmental Study – determination of
heavy metals in water, soil, and air
Food Industry – quality
assurance and testing for
contamination
Forensic’s –substance identification

25. Mining – testing the concentration
of valuable substances in potential
mining areas
Nuclear Energy – monitoring
potentially hazardous elements in
water and waste output
Petrochemical – analyzing
products for metals and other
substances that can have adverse
affects such as oil and gas
Pharmaceutical – many
applications from quality control
to detecting impurities in drugs